Instructions

1. In a skillet, heat 1 tablespoon of unsalted butter over medium heat. Add the sliced onions and a pinch of salt. Cook, stirring occasionally, until the onions are caramelized and golden brown, about 10 minutes. Remove from the skillet and set aside.
2. In the same skillet, add the remaining tablespoon of butter. Once melted, add the sliced mushrooms and season with salt and pepper. Cook for about 5 minutes, until they release their moisture and become golden brown. Remove from the skillet and set aside.
3. Spread butter on one side of each slice of bread.
4. On a clean surface, place two slices of bread, buttered side down. Layer each slice with a slice of cheddar cheese, followed by an even distribution of caramelized onions and sautéed mushrooms. Top with another slice of cheddar cheese.
5. Cover with the remaining bread slices, buttered side up.
6. Heat a skillet or griddle over medium heat. Place the sandwiches in the skillet and cook until the bread is golden brown and the cheese is melted, about 3-4 minutes per side. If needed, press down gently on the sandwiches with a spatula to encourage even toasting.
7. Once cooked, remove from the skillet and let cool for a few minutes before slicing in half. Serve hot and enjoy your savory creation!