Description
This French Onion Grilled Cheese Sandwich combines rich caramelized onions with layers of Swiss cheese between thick slices of buttered bread. The sandwich is cooked slowly on a griddle and steamed briefly to achieve a perfectly golden crust and melty cheese, making it an indulgent and flavorful comfort food.
Ingredients
Scale
Onion Mixture
- 2 tablespoons salted butter softened
- 2 medium yellow onions thinly sliced
- water as needed
- salt to taste
- pepper to taste
- ½ teaspoon fresh thyme leaves roughly chopped
- 1 teaspoon Worcestershire sauce
- 1 teaspoon sugar
- 1 teaspoon sherry vinegar or red wine vinegar
Sandwich
- 4 thick slices bread
- 6 slices Swiss cheese
- more butter for buttering the bread
Instructions
- Caramelize Onions: Melt 2 tablespoons of butter in a large sauté pan over medium heat, then add the sliced onions. Stir and cover, cooking until softened, about 5 minutes. Add a splash of water and scrape any browned bits from the pan. Cover again and continue cooking, repeating the process of adding water and scraping, until onions turn deep brown and caramelized, which takes approximately 30-35 minutes.
- Season Onions: Add the fresh thyme, Worcestershire sauce, sugar, and sherry or red wine vinegar to the caramelized onions. Season with salt and pepper to taste. Cook for an additional 2-3 minutes to combine flavors, then transfer the onions to a bowl.
- Assemble Sandwiches: Spread a layer of the caramelized onions on each slice of bread. On two slices, top with a folded slice of Swiss cheese. Add more onions, then another cheese slice, followed by more onions, and one last slice of cheese. Place the remaining two slices of bread on top, pressing gently to hold the sandwich together.
- Cook Sandwiches: Preheat a large sauté pan or griddle over medium-low heat. Butter one side of each sandwich, then place them butter-side-down on the pan. Cook until the bread is golden brown, about 4 minutes. Butter the top side of the sandwiches while the bottom cooks. Flip carefully and cook until the other side is golden. To melt the cheese evenly, splash a little water into the pan, then cover the sandwiches with an inverted large bowl for 1-2 minutes to create steam which melts the cheese.
- Serve: Transfer sandwiches to a cutting board and slice diagonally with a serrated knife. Serve immediately to enjoy the warm, gooey interior.
Notes
- Use a sturdy bread like sourdough or artisan white bread for the best structure and flavor.
- If you prefer a sharper cheese, substitute or add Gruyère or cheddar with the Swiss cheese.
- To speed up caramelizing onions, you can add a pinch of baking soda to the onions to help break them down, but this changes texture slightly.
- For a vegetarian version, ensure Worcestershire sauce used is vegetarian-friendly or omit it.
- Covering the sandwiches with a bowl to trap steam is key to fully melting the cheese without burning the bread.
Nutrition
- Serving Size: 1 sandwich
- Calories: 650 kcal
- Sugar: 9 g
- Sodium: 900 mg
- Fat: 38 g
- Saturated Fat: 22 g
- Unsaturated Fat: 14 g
- Trans Fat: 0.5 g
- Carbohydrates: 45 g
- Fiber: 4 g
- Protein: 22 g
- Cholesterol: 85 mg
