Ingredients
1 pound ground pork
1 tablespoon fennel seeds, lightly crushed
1 1/2 ounces Parmigiano-Reggiano, grated (1/3 cup)
Kosher salt and freshly ground pepper
2 tablespoons extra-virgin olive oil, plus more for drizzling
2 red or yellow bell peppers, cored and cut into 1/2-inch strips (2 cups)
1 onion, cut into 1/2-inch slices (1 1/2 cups)
1 can tomato sauce (15 ounces)
3 thick slices crusty boule, halved
6 ounces fresh mozzarella
Thinly sliced fresh basil leaves, for serving
Preparation
Mix together pork, fennel, Parmigiano, 3/4 teaspoon salt, and 1/2 teaspoon pepper in a bowl. Form into 1 1/2-inch balls. Heat oil in a large straight-sided skillet over medium-high. Add meatballs and cook, turning occasionally, until golden brown, 5 to 6 minutes; transfer to a plate.
Add peppers, onion, and 1/4 cup water to skillet and cook, stirring occasionally, 4 to 6 minutes. Stir in tomato sauce and 3/4 cup water. Season with salt and pepper and return meatballs and any accumulated juices to pan. Bring to a boil, then reduce heat to low. Partially cover skillet and simmer until meatballs are cooked through, about 10 minutes.
Preheat broiler, with rack 6 inches below element. On a baking sheet, drizzle both sides of bread with oil. Broil, flipping once, until toasted. Nestle into skillet and top everything with mozzarella. Broil until cheese melts, about 2 minutes. Sprinkle with basil and serve.
