Ingredients

• 2 tablespoons unsalted butter
• 1 1/4 lbs butternut squash, peeled,seeded and cut into 1/4 inch slices
• 1 1/4 lbs yukon gold potatoes, peeled and cut into 1/4 slices
• 1 cup half-and-half
• 1 teaspoon salt
• 2 cups packed grated gruyere cheese
• 1 1/2 tablespoons chopped fresh sage
• 4 cups thinly sliced onions
• 1/2 teaspoon ground black pepper
• 2 cups fresh breadcrumbs (preferably sourdough)