INGREDIENTS
2 tbsp
unsalted butter
4 larges
onions
1 pinch
salt and pepper
2 tsp
fresh thyme
2 tbsp
balsamic vinegar
2 cloves
garlic
1/2 cup
beef broth
1 tbsp
olive oil
4
skinless boneless chicken breasts
2 tsp
garlic powder
1 tsp
ground thyme
1 cup
gruyere cheese
4 tbsp
parmesan cheese