Smoky bacon scents this Crispy Potato-Onion Cake filled with layers of sliced potato, buttery leek, and tender onion and topped with fresh thyme. Crispy Potato-Onion Cake Serves: Makes 6 to 8 servings Ingredients 6 slices bacon, chopped 5 tablespoons unsalted butter, divided 4 cups sliced yellow onion (about 2 large onions) 2 cups sliced leek