# Components:
→ For the Caramelized Onions
01 - 1 large yellow onion, thinly sliced
02 - 1 tablespoon unsalted butter
03 - 1 teaspoon olive oil
04 - 1/2 teaspoon salt
05 - 1/4 teaspoon freshly ground black pepper
06 - 1/2 teaspoon sugar (optional)
→ For the Sandwiches
07 - 4 slices sourdough or country-style bread
08 - 2 tablespoons unsalted butter, softened
09 - 4 slices sharp cheddar cheese
10 - 2 slices Swiss or Gruyère cheese
# Directions:
01 - In a skillet over medium-low heat, melt 1 tablespoon butter with 1 teaspoon olive oil. Add the sliced onion, salt, pepper, and sugar if using. Cook, stirring occasionally, until onions are deeply golden and caramelized, about 20–25 minutes. Remove from heat and set aside.
02 - Lay out the bread slices. Spread a thin layer of softened butter on one side of each slice. Place two slices, buttered side down, on a clean surface.
03 - Top each of the two bread slices with a slice of cheddar, a generous spoonful of caramelized onions, a slice of Swiss or Gruyère, and then finish with the remaining cheddar slices. Close the sandwiches with the remaining bread, buttered side up.
04 - Heat a skillet or griddle over medium heat. Add the sandwiches and cook for 3–4 minutes per side, pressing gently, until bread is golden and crisp, and cheese is melted.
05 - Remove from pan, let rest for 1 minute, then slice in half and serve hot.
