Melt 2 tablespoons of butter in a large skillet over medium-high heat. Add 1 minced onion, 2 chopped celery stalks, and 1 chopped carrot. Sauté for about 10 minutes until softened.

Crumble in 1 pound of spicy Italian sausage, break it up, and sprinkle in 1 teaspoon of oregano, ½ teaspoon of red pepper flakes, salt, and pepper. Cook for 5-7 minutes until browned.

Pour in ½ cup of red wine and let simmer for about 2 minutes, scraping up browned bits from the skillet.

Stir in 1 can of San Marzano tomatoes and bring to a simmer. Cook uncovered for 20-30 minutes until the sauce thickens.

Bring a pot of salted water to a boil, add 12 ounces of rigatoni, and cook according to package instructions until al dente. Drain, reserving 1 cup of pasta water.

Combine the drained rigatoni with the sauce in the skillet, tossing gently. Add reserved pasta water as needed for consistency.

Serve in bowls, garnished with grated Parmesan cheese, chopped parsley, or butter.