In a large bowl combine ground meats (or single meat if using sausage links instead of meatballs), breadcrumbs, milk, egg, grated Parmesan, minced garlic, chopped parsley, dried oregano, kosher salt and black pepper. Mix gently with your hands or a fork until just combined; avoid overworking the meat to keep meatballs tender.

Form meatballs

Portion mixture into roughly 1 1/4-inch (about 1.5 tablespoon) portions to make about 18–20 small meatballs, or larger if you prefer. Roll gently between your palms to form smooth balls. If using sausage option, you can skip forming meatballs and instead use 12 oz of Italian sausage links (remove casings for loose sausage) or slice links into 1-inch thick pieces.

Brown meatballs

Heat 2 tablespoons olive oil in a large skillet over medium-high heat. Add meatballs (work in batches if necessary) and cook, turning occasionally, until browned on all sides but not cooked through, about 6–8 minutes total. Transfer browned meatballs to a plate and set aside. If using sausage links, brown slices or whole links until nicely caramelized, 5–7 minutes.

Tomato Sauce

Sauté aromatics

In a large deep skillet or Dutch oven, heat 1 tablespoon extra-virgin olive oil over medium heat. Add the chopped onion and cook until softened and translucent, about 5 minutes. Add 2 minced garlic cloves and cook until fragrant, about 30 seconds.

Build the sauce

Stir in the tomato paste and cook 1 minute to deepen flavor. Add crushed tomatoes, 1/2 cup water or broth, dried basil, dried oregano, red pepper flakes (if using), sugar (if using), salt and pepper. Stir to combine and bring to a gentle simmer.

Simmer with meat

Return the browned meatballs (or sausage pieces) to the sauce, nestling them into the tomatoes. Reduce heat to low and simmer gently, uncovered or partially covered, for 20–25 minutes until meatballs are cooked through (internal temperature 160°F/71°C for pork/beef) and sauce thickens. Taste and adjust seasoning. If using whole sausage links, ensure they reach 160°F and cook covered for slightly longer if needed.

Finish sauce

If using, stir in torn fresh basil leaves in the final 2 minutes. For a silkier sauce, skim out a couple tablespoons of sauce into a small bowl and whisk in a tablespoon of cold butter, then stir back in (optional). Keep warm until ready to serve.

Pasta & Assembly

Cook pasta

Bring a large pot of water to a rolling boil. Add 1 tablespoon salt. Add pasta and cook according to package directions until al dente. Reserve 1 cup of pasta cooking water, then drain the pasta.

Combine pasta and sauce

Add drained pasta to the sauce and gently toss to combine, adding reserved pasta water a few tablespoons at a time as needed to loosen the sauce and help it cling to the pasta (typically 2–1/4 to 1/2 cup). If serving meatballs over pasta rather than mixed, spoon sauce over plated pasta and top with meatballs.

Serve

Divide among 4 plates (servings). Sprinkle with grated Parmesan and chopped parsley, and drizzle a little olive oil if desired. Serve hot.