Sautéed Spinach, Mushrooms, and Caramelized Onions is a versatile, flavor-packed side dish that pairs beautifully with chicken, steak, pasta, or grains. Built on the natural sweetness of slow-caramelized onions, the earthiness of mushrooms, and the freshness of spinach, this recipe brings restaurant-quality flavor to your home kitchen. Add the optional creamy Parmesan sauce for a richer, more indulgent version. Whether served as a healthy side, a topping for proteins, or even as a vegetarian main, this dish offers warmth, comfort, and incredible depth.
Why You’ll Love This Recipe
You’ll love this recipe because it transforms simple ingredients into a rich, savory, and satisfying dish. The caramelized onions add complexity and sweetness, mushrooms bring hearty umami, and spinach adds freshness and nutrition. Everything cooks in one skillet, making it easy, convenient, and perfect for weeknights. The optional cream sauce elevates it into a luxurious, silky dish ideal for serving with pasta or as a comforting vegetarian entrée. It’s healthy, flavorful, and endlessly adaptable.
Sautéed Spinach, Mushrooms, and Caramelized Onions
Sautéed Spinach, Mushrooms, and Caramelized Onions is one of those recipes that highlights the beauty of simple ingredients cooked with care. While each component is delicious on its own, combining them creates layers of flavor that are savory, sweet, and deeply satisfying. Whether served as a side dish or enjoyed stand-alone, it delivers a comforting and wholesome experience perfect for any mealtime.
The heart of this dish is the caramelized onions. Slow-cooked until golden, soft, and sweet, caramelized onions bring a richness that transforms the entire skillet. Their natural sugars develop over a low flame, creating a flavor that is hard to replicate with any shortcut. When added back into the pan with mushrooms and spinach, they provide a powerful base of sweetness and complexity.
Mushrooms are another essential component, bringing their trademark earthiness and umami depth. As they cook, they release moisture, concentrate in flavor, and develop a wonderful golden color. Whether you choose button mushrooms, shiitakes, baby bellas, or a mix, the mushrooms form a savory backbone that pairs beautifully with the onions and the fresh, delicate spinach.
Spinach adds brightness and freshness to the dish, balancing the deeper flavors with its mild, vibrant green notes. As it wilts into the mushrooms, it absorbs the aromatics and pan juices, becoming tender and flavorful rather than watery or bland. Combined, the three vegetables create a perfect harmony in texture and taste.
This dish becomes even more luxurious with the optional creamy Parmesan sauce. Adding heavy cream, milk, and melted Parmesan transforms the sautéed vegetables into a velvety, indulgent dish reminiscent of restaurant-style creamed spinach—but with far more complexity thanks to the mushrooms and onions. This variation makes it an excellent topping for pasta, chicken, or even baked potatoes.
The beauty of this recipe lies not only in its flavor but also in its versatility. It works beautifully as a side dish, yet it can also be served as a vegetarian main when paired with rice, quinoa, or couscous. You can fold it into omelets, layer it over toast, stuff it into wraps, or spoon it over grilled proteins. It’s a recipe you’ll turn to again and again because it’s endlessly flexible.
Another reason this recipe is so appealing is that it uses pantry staples and simple produce. Onions, mushrooms, spinach, garlic, and olive oil are items many kitchens already have on hand, making this dish convenient and budget-friendly. And while it may taste like something slow-cooked and elaborate, the steps are straightforward and achievable for cooks of all skill levels.
Cooking everything in the same skillet also means minimal cleanup, which is always a win for busy weeknights. The onions caramelize slowly in the same pan where the mushrooms and spinach cook, allowing each component to develop deep flavor without extra dishes. The optional creamy sauce is made in that same pan as well, allowing all the flavors to meld seamlessly.
For those who enjoy meal prepping, this recipe holds up incredibly well. The vegetables reheat beautifully without turning mushy or losing flavor, making it a great option for storing in the refrigerator for several days. It’s one of those dishes that tastes just as good the next day—if not better—because the flavors continue to deepen.
Above all, this dish is comforting, savory, and wholesome. Whether you’re looking for a nutritious vegetable side or a flavorful base for a larger meal, Sautéed Spinach, Mushrooms, and Caramelized Onions delivers on every level. It’s easy, delicious, and satisfying—everything you want in a go-to recipe you’ll make again and again.
Servings & Time
Servings: 4–6
Prep Time: 10 minutes
Cook Time: 35–40 minutes
Total Time: 45–50 minutes
Ingredients
Caramelized Onions
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1 tablespoon olive oil
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3 medium or large onions, sliced
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Pinch of salt
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1 tablespoon balsamic vinegar
Cooked Mushrooms & Spinach
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1 tablespoon olive oil
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8 oz mushrooms (button, shiitake, etc.), sliced
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3 garlic cloves, minced
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Pinch of salt
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6 oz fresh spinach
Optional Cream Sauce
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⅓ cup heavy cream
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¼ cup milk
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½ cup shredded Parmesan cheese
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¼ teaspoon salt
Instructions
Caramelize the Onions
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Heat olive oil in a large skillet over medium-high heat.
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Add sliced onions and cook for 10 minutes, stirring constantly.
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Reduce heat to medium and cook for 10 more minutes, stirring frequently.
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Add a pinch of salt.
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Continue cooking for another 10 minutes on medium or low heat.
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Remove from heat and add balsamic vinegar.
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Stir to deglaze the pan and coat the onions.
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Transfer onions to a plate.
Cook Mushrooms & Spinach
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Heat olive oil in the same skillet over medium heat.
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Add mushrooms and sprinkle with salt.
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Cook for 5 minutes, stirring occasionally.
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Add spinach and stir on low heat until wilted.
Make the Cream Sauce (Optional)
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Add heavy cream and milk to the skillet.
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Bring to a brief boil, then reduce to a simmer.
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Add Parmesan and salt.
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Stir until cheese melts and sauce thickens.
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Add caramelized onions back to the skillet.
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Adjust thickness with more cream (to thin) or Parmesan (to thicken).
Tips
Ingredient Substitutions
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Use kale or Swiss chard instead of spinach.
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Replace Parmesan with Pecorino Romano for sharper flavor.
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Add thyme or rosemary for herbal depth.
Make-Ahead & Storage
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Keeps for 3–4 days in the fridge.
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Reheat gently on the stovetop.
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Freezing is not recommended for the creamy version.
Serving Variations
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Serve over grilled chicken, steak, or tofu.
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Toss with pasta for a full meal.
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Add to omelets, sandwiches, or wraps.
Avoid Common Mistakes
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Don’t rush the onions—proper caramelization takes at least 30 minutes.
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Avoid overcrowding the mushrooms or they’ll steam instead of brown.
-
Add spinach last to prevent overcooking.
Sautéed Spinach, Mushrooms, and Caramelized Onions
Ingredients
Caramelized Onions
- 1 tablespoon olive oil
- 3 medium or large onions sliced
- Pinch of salt
- 1 tablespoon balsamic vinegar
Cooked Mushrooms & Spinach
- 1 tablespoon olive oil
- 8 oz mushrooms button, shiitake, etc., sliced
- 3 garlic cloves minced
- Pinch of salt
- 6 oz fresh spinach
Optional Cream Sauce
- ⅓ cup heavy cream
- ¼ cup milk
- ½ cup shredded Parmesan cheese
- ¼ teaspoon salt
Instructions
Caramelize the Onions
- Heat olive oil in a large skillet over medium-high heat.
- Add sliced onions and cook for 10 minutes, stirring constantly.
- Reduce heat to medium and cook for 10 more minutes, stirring frequently.
- Add a pinch of salt.
- Continue cooking for another 10 minutes on medium or low heat.
- Remove from heat and add balsamic vinegar.
- Stir to deglaze the pan and coat the onions.
- Transfer onions to a plate.
Cook Mushrooms & Spinach
- Heat olive oil in the same skillet over medium heat.
- Add mushrooms and sprinkle with salt.
- Cook for 5 minutes, stirring occasionally.
- Add spinach and stir on low heat until wilted.
Make the Cream Sauce (Optional)
- Add heavy cream and milk to the skillet.
- Bring to a brief boil, then reduce to a simmer.
- Add Parmesan and salt.
- Stir until cheese melts and sauce thickens.
- Add caramelized onions back to the skillet.
- Adjust thickness with more cream (to thin) or Parmesan (to thicken).
Notes
Ingredient Substitutions
- Use kale or Swiss chard instead of spinach.
- Replace Parmesan with Pecorino Romano for sharper flavor.
- Add thyme or rosemary for herbal depth.
Make-Ahead & Storage
- Keeps for 3–4 days in the fridge.
- Reheat gently on the stovetop.
- Freezing is not recommended for the creamy version.
Serving Variations
- Serve over grilled chicken, steak, or tofu.
- Toss with pasta for a full meal.
- Add to omelets, sandwiches, or wraps.
Avoid Common Mistakes
- Don’t rush the onions—proper caramelization takes at least 30 minutes.
- Avoid overcrowding the mushrooms or they’ll steam instead of brown.
- Add spinach last to prevent overcooking.
