disable dropcap
- 1 small onion, chopped
- 2 celery stalks, chopped
- 1 carrot, chopped
- 1 teaspoon red-pepper flakes (or to taste)
- 2 tablespoons olive oil
- 1 tablespoon flour
- 1 cup milk, plus one tablespoon
- 1/4 teaspoon freshly grated nutmeg
- 3 to 4 large sweet potatoes, peeled and thinly sliced (ideally with a mandoline)
- 1 6-ounce package frozen spinach, thawed and drained
- 1 1/2-pound ball fresh mozzarella, sliced thinly or 1/2 pound bocconcini, halved
- 1 cup fresh ricotta
- 3/4 cup Parmesan, grated
- In a medium saucepan over medium heat, sauté the onion, celery, carrot, and red-pepper flakes in the olive oil until the vegetables are soft, about 10 minutes.
- Add the flour and stir for about a minute.
- Whisk in the milk and nutmeg and heat until warmed through.
- Spread one-third of the onion mixture on the bottom of a 9-by-13-inch baking dish. Layer one-third of the potatoes, mozzarella or bocconcini slices, ricotta, spinach, and Parmesan and repeat in three layers, ending with just Parmesan, mozzarella, and a little milk around the edges.
- Bake, covered with foil, at 425 °F for 1 hour, removing the foil for final 10 minutes so the top can crisp up and get bubbly.
