Ingredients
1 Medium yellow onion, sliced
Olive oil
1 tsp. sugar
2 T. beef stock
salt
pepper
2 chicken breasts
3/4 cup mozzarella, shredded
Instructions
Heat a drizzle of oil in the pan over medium high heat. Add onion and cook, stirring, until lightly browned, 8 - 10 minutes. Add sugar and reduce heat to medium. Cook, stirring, until browned and softened, about 4 minutes. Stir in stock, salt, and pepper. Cook, stirring until liquid has evaporated and onion has jam like consistency, about 2 minutes. Remove onions to plate and wipe out skillet.
Pat chicken dry with paper towels, season all over with salt and pepper. Heat a drizzle of oil in the pan and cook chicken on first side for 4 minutes. Flip and cook for 2 minutes more, then evenly top with onions and mozzarella. Cover pan and cook until cheese has melted, about 2 minutes. Serve.