Scalloped Potatoes with Tomatoes

Ingredients

• 1 cups whole milk
• 1 cups heavy cream
• 1 cup white wine
• 1/2 cup flour
• 1/4 cup butter
• 1/2 teaspoon freshly grated nutmeg
• Kosher salt and freshly ground pepper
• 1 pound russet potatoes, peeled, sliced 1/8 inch thick and patted dry
• 1 1/2 cups coarsely grated gruyere cheese (about 6 ounces)
• 4 plum tomatoes, sliced 3/4 inch thick
• 2 bell peppers (yellow or orange), cut into 3/4-inch-thick strips
• 1 onion, halved and sliced 1/2 inch thick
• 3 teaspoons herbes de Provence
• 1/2 cup breadcrumbs (optional)