Take everything you love about French onion soup — the sweet caramelized onions, gooey melted cheese, and rich savory flavor — and tuck it between two slices of buttery toasted bread. That’s exactly what this French Onion Grilled Cheese delivers.
It’s comforting, elegant, and indulgent — perfect for lunch, dinner, or even a cozy midnight snack.
Why You’ll Love This Recipe
- Savory & sweet – Caramelized onions add depth and richness.
- Cheesy & gooey – Gruyère or Swiss cheese melts beautifully.
- Easy upgrade – Turns a simple grilled cheese into a gourmet treat.
- Pairs perfectly – Serve with soup, salad, or even wine.
Ingredients You’ll Need
- 4 slices hearty bread (sourdough, rustic white, or rye)
- 2 large onions, thinly sliced
- 2 tbsp butter (plus more for toasting bread)
- 1 tbsp olive oil
- ½ tsp salt
- ½ tsp sugar (optional, helps onions caramelize)
- 2 tsp fresh thyme (or 1 tsp dried)
- 1 tsp balsamic vinegar (optional, for tang)
- 1 cup shredded Gruyère cheese (or Swiss / provolone)
- 2 slices mozzarella or fontina (extra melty goodness)