Herby The Scalloped Potato

Ingredients 5 medium to large potatoes sliced 1/8″ thick 2 medium yams sliced 1/8″ thick 3 tbsp bacon fat or butter 1 small onion or 2 large shallots diced 1 large clove garlic minced 5 sprigs of thyme stripped 1 sprig of rosemary chopped 3 tbsp flour 2 cups milk 1-1/2 cup gruyere cheese shredded…