Put yourself in a New York state of mind with some sausage and peppers. We take this East Coast stalwart off the bun and turn it into a killer pasta dish. Fennel seed-flecked Italian sausage gets pan-seared and tossed with tender bell peppers and al dente tubes of rigatoni. A zesty marinara marries the whole thing together for a meal that's simple to prepare but hard to forget. Fuhgeddaboudit.
Stem, seed, and slice both green and red bell peppers into thin ¼" strips. Peel and halve onion. Slice halves thinly. Mince garlic.
Remove sausage from casing.
Cook the Sausage
Heat 1 tsp. olive oil in a large pan over medium-high heat. Add sausage to hot pan and cook, breaking up into pieces, until browned, 3-4 minutes.
Transfer sausage to a plate.
Reserve pan; no need to wipe clean.
Cook the Pasta
Add pasta to boiling water. Cook until al dente, 11-13 minutes. Reserve ½ cup pasta cooking water, then drain pasta in colander. Return pasta to pot and toss with 2 tsp. olive oil to prevent sticking. Set aside. While pasta boils, cook vegetables.
Cook the Vegetables
Return pan used to cook sausage to medium-high heat and add 1 tsp. olive oil. Add peppers, onion, garlic, and red pepper flakes (to taste) to hot pan. Reduce heat to medium, stir, and cover. Cook until vegetables are softened, 5-7 minutes.
Finish the Sauce
Add sausage, marinara, and reserved pasta cooking water to pan. Simmer, stirring occasionally, 4-5 minutes. Stir in spinach, pasta, half the Parmesan (reserve remaining for garnish). Cook until spinach wilts slightly and sausages reach a minimum internal temperature of 165 degrees, 1-2 minutes.
Place pasta on a plate or in a shallow bowl. Garnish with Parmesan.