Caramelized Onion and Mushroom Quesadilla Recipe
Introduction
This Caramelized Onion and Mushroom Quesadilla is a flavorful twist on a classic favorite. With sweet caramelized onions, savory mushrooms, and melty cheese wrapped in toasted tortillas, it’s an easy meal that’s perfect for any time of day.

Ingredients
- 2 Tablespoons olive oil
- 2 onions, sliced
- 2 teaspoons brown sugar
- 1/3 cup balsamic vinegar
- 1 ½ Tablespoons unsalted butter
- 3 large garlic cloves, minced
- 4 large portobello or mushrooms of choice, thinly sliced
- 3 thyme sprigs (use just the leaves)
- 8 flour tortillas
- 1 cup grated sharp cheddar (or cheese of choice)
- 1 cup spinach/arugula mix, rough chopped
- 1/2 cup sour cream
- Juice of 1/2 lemon
Instructions
- Step 1: In a medium skillet, heat 1 tablespoon of olive oil over low heat. Add sliced onions and stir occasionally, cooking until soft, about 10 to 12 minutes.
- Step 2: Add brown sugar and balsamic vinegar to the onions. Cook for another 5 minutes or until onions are caramelized. Remove from heat and transfer onions to a plate or bowl. Set aside.
- Step 3: In the same skillet, heat butter and the remaining tablespoon of olive oil over medium heat. Add minced garlic, sliced mushrooms, and thyme leaves. Stir and cook for 3 to 4 minutes until mushrooms are soft. Remove from heat and set aside.
- Step 4: Heat a grill or grill pan over high heat. Toast the tortillas one at a time until they are slightly charred. Place each toasted tortilla, toasted side up, on a clean surface.
- Step 5: Divide the caramelized onions, mushroom mixture, grated cheese, and chopped spinach/arugula evenly over four of the tortillas. Top each with a remaining tortilla, toasted side down, to form a quesadilla.
- Step 6: Return the grill pan to high heat. Place each quesadilla on the grill pan and cook for 2 to 3 minutes until the bottom is toasted.
- Step 7: Flip the quesadilla and cook for another 1 to 2 minutes until the other side is toasted and the cheese has melted.
- Step 8: To make the lemon sour cream, combine sour cream and lemon juice in a small bowl. Mix thoroughly and serve alongside the quesadillas.
Tips & Variations
- Use a mix of your favorite mushrooms for deeper flavor.
- Try swapping cheddar for Monterey Jack or mozzarella for a different cheese experience.
- Add a pinch of chili flakes to the mushroom mixture for a subtle heat.
- For a gluten-free option, use corn or gluten-free tortillas.
- Serve with guacamole or salsa for added freshness.
Storage
Store leftover quesadillas in an airtight container in the refrigerator for up to 3 days. Reheat in a skillet or grill pan over medium heat to keep the tortillas crispy. The lemon sour cream is best served fresh but can be refrigerated for up to 2 days.
How to Serve

Serve this delicious recipe with your favorite sides.
FAQs
Can I use other types of cheese?
Yes, you can use any melting cheese you like such as Monterey Jack, mozzarella, or a Mexican cheese blend to suit your taste.
How do I prevent the tortillas from getting soggy?
To keep tortillas crispy, toast them before assembling the quesadilla and cook the assembled quesadilla over medium-high heat on a grill pan or skillet until both sides are nicely toasted and the cheese is melted.
Print
Caramelized Onion and Mushroom Quesadilla Recipe
- Total Time: 40 minutes
- Yield: 4 servings 1x
- Diet: Vegetarian
Description
This Caramelized Onion and Mushroom Quesadilla is a flavorful vegetarian dish combining sweet caramelized onions, tender sautéed mushrooms, melted sharp cheddar cheese, and fresh spinach and arugula, all sandwiched between perfectly toasted flour tortillas. Finished with a tangy lemon sour cream, it’s an easy yet sophisticated meal perfect for lunch or dinner.
Ingredients
For the Caramelized Onions
- 2 Tablespoons olive oil
- 2 onions, sliced
- 2 teaspoons brown sugar
- 1/3 cup balsamic vinegar
For the Mushroom Mixture
- 1 ½ Tablespoons unsalted butter
- 1 Tablespoon olive oil (remaining after onions)
- 3 large garlic cloves, minced
- 4 large portobello or mushrooms of choice, thinly sliced
- 3 thyme sprigs (leaves only)
For the Quesadilla
- 8 flour tortillas
- 1 cup grated sharp cheddar cheese (or cheese of choice)
- 1 cup spinach/arugula mix, roughly chopped
For the Lemon Sour Cream
- 1/2 cup sour cream
- Juice of 1/2 lemon
Instructions
- Caramelize the Onions: In a medium skillet, heat 1 tablespoon olive oil over low heat. Add the sliced onions and stir occasionally, cooking for about 10-12 minutes until soft and translucent. Then add the brown sugar and balsamic vinegar, cooking for another 5 minutes until the onions are richly caramelized. Remove from the skillet and set aside on a plate or bowl.
- Cook the Mushrooms: In the same skillet, heat the butter and the remaining 1 tablespoon olive oil over medium heat. Add the minced garlic, thinly sliced mushrooms, and thyme leaves. Stir and cook for 3-4 minutes until mushrooms are tender and flavorful. Remove from heat and set aside.
- Toast the Tortillas: Preheat a grill or grill pan over high heat. Toast the flour tortillas one at a time, cooking until slightly charred but still pliable. Remove and place 4 tortillas toasted side up on a cutting board for assembling.
- Assemble the Quesadillas: Spread an even quarter of the caramelized onion mixture onto each of the 4 toasted tortillas. Add an even quarter of the mushroom mixture, followed by one quarter of the grated cheese and the chopped spinach/arugula. Top each with one of the remaining toasted tortillas, placing them toasted side down to form the quesadillas.
- Cook the Quesadillas: Reheat the grill pan on high heat. Place each assembled quesadilla in the pan and cook for 2-3 minutes on one side until toasted. Flip carefully and cook the other side for an additional 1-2 minutes until the tortilla is golden and the cheese has melted through.
- Prepare the Lemon Sour Cream: In a small bowl, combine the sour cream with the juice of half a lemon. Mix thoroughly to create a tangy dipping sauce.
- Serve: Slice the quesadillas into wedges and serve warm with the lemon sour cream on the side for dipping.
Notes
- Substitute cheddar with any melty cheese like Monterey Jack or mozzarella if preferred.
- For a gluten-free version, use corn tortillas instead of flour tortillas.
- Ensure the mushrooms are sliced thinly to cook evenly and absorb flavors.
- Low and slow cooking is key to properly caramelize the onions without burning.
- This dish can be served with additional toppings like avocado or salsa for extra flavor.
- Prep Time: 15 minutes
- Cook Time: 25 minutes
- Category: Main Course
- Method: Stovetop
- Cuisine: Mexican-inspired
Keywords: caramelized onion quesadilla, mushroom quesadilla, vegetarian quesadilla, easy quesadilla recipe, grilled quesadilla, cheese quesadilla, healthy vegetarian meal

