This Ultimate Gourmet Grilled Cheese is loaded with herbed caramelized onions, gooey Gruyere and white cheddar cheeses, and is cooked in a savory rosemary butter!
Add 1 1/2 Tbsp butter and olive oil to a skillet and heat over MED-LOW heat. Add diced onions, salt, pepper, fresh thyme and 1 tsp of fresh rosemary to the hot skillet and saute, stirring often, until onions are soft and starting to brown, about 10 minutes.
Stir brown sugar into the onions and cook another minute.
Transfer onions to a plate.
Spread one side of two pieces of bread with a little bit of mayonnaise.
To the same skillet, add remaining butter and rosemary, and heat over MED heat. Swirl to coat the bottom of the skillet with the melted butter.
Add both pieces of bread, mayonnaise side down, and cook until bread is golden brown and crunchy, about 2-3 minutes.
As soon as you add the bread to the skillet, add a bit of cheese to the top of each piece of bread. Once it starts to melt a little, sprinkle a couple tablespoons of the caramelized onions over the top of one of the pieces of bread.
When the bread is good and golden brown, sandwich the pieces of bread together and cook on LOW until cheese is fully melted.
Transfer to a plate, repeat with remaining slices of bread and ingredients.
Slice and enjoy!
Servings 0