Slow Cooker French Onion Soup

Melt the butter in a large skillet, then add the sliced onions. Saute the onions until tender, about 5 minutes. Stir in the sugar, salt, and black pepper and continue to saute for 20 minutes, stirring occasionally.

Transfer the onions to the slow cooker. Add in the chicken stock, white wine, and thyme. Put the lid on and cook on low for 7 to 8 hours, or on high for 4 hours. Taste and add salt and pepper if needed.

Turn the oven-broiler on high. Ladle soup into ovenproof bowls. Top the bowls with a slice of French bread and cheese. Broil in oven until cheese is melted, 3 to 5 minutes.