Spinach, Mushrooms & Caramelized Onions Skillet

Simple Ingredients, Deep Flavor

Some of the most satisfying dishes come from the simplest ingredients treated with care. This Spinach, Mushrooms & Caramelized Onions Skillet is a perfect example. Built on slow-cooked onions, earthy mushrooms, and fresh spinach, this dish delivers bold, savory flavor without heaviness.

Caramelized onions add sweetness and depth, mushrooms provide umami richness, and spinach brings freshness and color. Everything comes together in one skillet, making it ideal for busy weeknights, healthy eating, or elegant side dishes for gatherings.

Whether served as a vegetarian main, a topping for toast or grains, or a flavorful side for proteins, this skillet recipe is endlessly versatile.

Why This Skillet Recipe Works

• One pan, minimal cleanup
• Naturally vegetarian and nutrient-rich
• Deep flavor from caramelization
• Easy to customize with herbs or cheese

It’s proof that vegetables can be comforting, rich, and crave-worthy.

The Power of Caramelized Onions

Caramelizing onions slowly transforms them from sharp and pungent into soft, golden strands packed with natural sweetness. This step forms the flavor foundation of the dish and balances the earthiness of the mushrooms beautifully.

Patience is key — low heat and time create magic.

INGREDIENTS

• 2 tablespoons olive oil
• 2 large onions, thinly sliced
• 8 oz mushrooms, sliced (button, cremini, or mixed)
• 4 cups fresh spinach
• 2 cloves garlic, minced
• ½ teaspoon salt
• ¼ teaspoon black pepper
• ¼ teaspoon dried thyme (optional)
• Splash of balsamic vinegar or lemon juice (optional)

INSTRUCTIONS

1. Heat olive oil in a large skillet over medium-low heat.
2. Add sliced onions and cook slowly, stirring occasionally.
3. Continue cooking onions for 15–20 minutes until deeply golden and caramelized.
4. Add mushrooms to the skillet and increase heat to medium.
5. Cook mushrooms until softened and lightly browned.
6. Stir in garlic, salt, pepper, and thyme.
7. Add spinach and cook until just wilted.
8. Finish with a splash of balsamic vinegar or lemon juice if desired.
9. Taste and adjust seasoning.
10. Serve warm directly from the skillet.

Flavor & Texture Profile

• Sweetness: Deep, mellow onion sweetness
• Umami: Rich mushrooms bring savory depth
• Freshness: Spinach adds balance and color

The result is a harmonious, comforting vegetable dish with restaurant-quality flavor.

Serving Ideas

• Serve over toast or crusty bread
• Spoon onto rice, quinoa, or pasta
• Pair with eggs for breakfast or brunch
• Use as a side for grilled meats or fish

It’s equally at home on a casual table or a dinner-party spread.

Storage & Reheating

• Refrigerate leftovers up to 3 days
• Reheat gently in a skillet
• Add a splash of water or oil if needed

Flavors deepen even more the next day.

Spinach, Mushrooms & Caramelized Onions Skillet

A savory one-pan skillet featuring caramelized onions, sautéed mushrooms, and fresh spinach, perfect as a vegetarian main or flavorful side dish.

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Prep Time 10 minutes mins

Cook Time 25 minutes mins

Total Time 35 minutes mins

Servings: 4 servings

Course: Main, Side Dish

Cuisine: Mediterranean, Vegetarian

Calories: 150

Ingredients Equipment Method Notes

Ingredients

  

• 2 tbsp olive oil
• 2 large onions thinly sliced
• 8 oz mushrooms sliced
• 4 cups fresh spinach
• 2 cloves garlic minced
• 0.5 tsp salt
• 0.25 tsp black pepper

Equipment

• Large skillet
• Wooden spoon

Method

 

1. Caramelize onions slowly in olive oil.
2. Add mushrooms and cook until browned.
3. Stir in garlic, spinach, and seasonings until wilted.

Notes

Cook onions slowly for maximum sweetness and depth of flavor.