Gooey Garlic Bread Grilled Cheese Sandwich

0 Prepare the onions. Heat olive oil in a large skillet over medium heat. Add onions and cook until transparent and fragrant, about 8 minutes. Add stock and let it simmer until it completely disappears. Pour wine and let it reduce. Remove from heat.
2 Prepare garlic butter. Combine 5 tsp of room temperature butter with one clove of minced garlic, and salt and pepper to taste. 
4 Assemble the garlic bread grilled cheese sandwich. Top a slice of whole grain bread with around ¼ cup french onion and ¼ cup cheddar cheese. Cover with another slice of  bread. Spread ½ tsp of garlic butter on the outer layer of both slices of bread (you'll use 1 tsp per sandwich). Repeat the process to create 4 sandwiches.
6 In a large skillet over medium heat melt the remaining 1 tsp of butter. Add the thyme sprigs and cook for 2 minutes or until fragrant. 
8 Place the sandwiches in the skillet and cook for 3 minutes per side or until golden brown.