Grilled Cheese With Onion and Mushrooms

• 1 medium onion
• 2 tablespoons butter
• 1 cup mushroom, sliced
• sea salt
• 1 teaspoon balsamic vinegar
• 4 slices swiss cheese
• 8 slices sourdough bread

1. Slice the onion and saute in butter over medium heat until soft and golden brown, about 7-10 minutes, stirring occasionally.
2. Stir in mushrooms, cook at stir 2-3 minutes more; remove from heat.
3. Sprinkle onions and mushroom with sea salt and balsamic vinegar.
4. Place slices of cheese on 4 pieces bread, top each with onion-mushroom mixture and another slice of bread.
5. Cook on a griddle or skillet over medium heat until cheese is melted, 2-3 minutes per side.

onion, butter, mushroom, salt, balsamic vinegar, swiss cheese, bread

Taken from www.food.com/recipe/grilled-cheese-with-onion-and-mushrooms-211733 (may not work)