Garlic Parmesan Au Gratin Potatoes

INGREDIENTS

1 tbsp

unsalted butter, softened

1 1/2 lb

russet potatoes (roughly 4 large potatoes), peeled and thinly sliced (preferably with a mandoline for even, thin cuts)

1/2 cup

chopped onion

garlic cloves, minced

1 1/4 cups

shredded Parmigiano Reggiano

1 tsp

fresh thyme

1/2 tsp

salt

1/4 tsp

pepper

1 cup

heavy whipping cream