Description
A melty, savory twist on a classic grilled cheese, this French Onion Soup Grilled Cheese blends caramelized onions, rich Gruyère, and crispy sourdough for a comforting, café-worthy sandwich.
Ingredients
Scale
- 2 large yellow onions, thinly sliced
- 2 tablespoons butter
- 1 tablespoon olive oil
- 1/2 teaspoon salt
- 1 teaspoon fresh thyme
- 1 cup shredded Gruyère cheese
- 1/2 cup shredded mozzarella cheese
- 4 slices thick-cut sourdough bread
- Mayonnaise or softened butter (for spreading)
Instructions
- Place a skillet over medium heat to preheat while slicing the onions.
- Melt butter and olive oil in the skillet. Add onions and salt, cooking slowly for 25–30 minutes until deep golden brown. Stir in thyme and remove from heat.
- Wipe the skillet or use a clean one, then preheat over medium-low heat.
- Spread mayonnaise or butter on one side of each bread slice. On the unbuttered sides, layer Gruyère, caramelized onions, mozzarella, and top with the second slice.
- Place sandwich in the skillet, buttered side down. Cook 3–4 minutes per side until golden and cheese melts. Press gently with a spatula.
- Let rest for a minute before slicing. Garnish with thyme if desired.
- Slice and serve warm, optionally with salad or broth for dipping.
Notes
- Use thick bread to avoid sogginess from the onions.
- Caramelize onions ahead to save time later.
- Use a mix of cheeses for ideal melt and flavor.
- Reheat in a skillet to keep the bread crispy.
Nutrition
- Serving Size: 1 sandwich
- Calories: 530
- Sugar: 6g
- Sodium: 720mg
- Fat: 32g
- Saturated Fat: 17g
- Unsaturated Fat: 13g
- Trans Fat: 0g
- Carbohydrates: 40g
- Fiber: 3g
- Protein: 18g
- Cholesterol: 65mg
Keywords: French onion soup grilled cheese, gourmet grilled cheese, caramelized onion sandwich, cheesy sandwich, vegetarian grilled cheese