Slow Cooker Shrimp in Purgatory

Step 1

In a 6- to 8-quart slow cooker, combine the oil, onion, roasted red peppers, Calabrian chiles, garlic, oregano, red-pepper flakes, fennel seeds and tomatoes. (Crush the tomatoes by hand if using whole.) Season with 1/2 teaspoon salt and several generous grinds of black pepper. Stir well to combine, then cover and cook on high for 5 hours. (The sauce holds well on warm for up to an additional 3 hours.)

Step 2

Increase the heat to high if it has switched to warm. Stir in the shrimp, capers and scallions. Cover and cook until the shrimp are curled and opaque, 15 to 20 minutes, depending on size and quantity. Turn off the heat and taste the sauce. Add more red-pepper flakes and salt and pepper, if you like. Sprinkle the cheese over the top and serve, passing more Parmesan and red-pepper flakes at the table.