Golden grilled bread filled with caramelized onions, Dijon mustard, and a rich blend of melted Gruyère and Swiss cheese.

2 tbsp unsalted butter

1 large onion, thinly sliced

4 slices sourdough bread

2 tbsp mayonnaise

2 tbsp Dijon mustard

2 cups shredded Gruyère cheese

2 cups shredded Swiss cheese

Salt, to taste

Black pepper, to taste

Cook Mode Prevent your screen from going dark

1. Melt butter and caramelize onions until golden.

2. Season onions with salt and pepper.

3. Spread mayonnaise on one side of bread and Dijon on the other.

4. Layer cheeses and onions onto bread slices.

5. Top with remaining bread slices.

6. Grill sandwiches in butter until golden and crisp.

7. Flip and cook until cheese is fully melted.

8. Serve immediately while hot.

Caramelize onions slowly for best flavor.

Use freshly shredded cheese for a smoother melt.

Serve with tomato soup or a green salad.

Store leftovers refrigerated up to 2 days.