In a large bowl combine ground beef, ground pork, soaked breadcrumbs (with any remaining milk), grated Parmesan, minced garlic, chopped parsley, dried oregano, salt and black pepper. Crack in the egg. Use clean hands to gently mix until evenly combined; avoid overworking to keep meatballs tender.

Form meatballs

Shape the mixture into meatballs about 1 1/4 inch (roughly golf-ball size). You should get approximately 18–20 meatballs. Place them on a baking sheet or plate while you heat the pan.

Brown meatballs

Heat 2 tablespoons olive oil in a large skillet over medium-high heat. Working in batches to avoid crowding, add meatballs and brown on all sides, turning carefully with tongs or a spoon, about 6–8 minutes total per batch. They do not need to be fully cooked through. Transfer browned meatballs to a plate and set aside.

Sauce

Sauté aromatics

In the same skillet (wipe out if there's excessive fat, leaving a tablespoon for flavor) add 1 tablespoon olive oil over medium heat. Add the finely diced onion and cook until translucent, about 5–6 minutes. Add the minced garlic and cook 30–45 seconds until fragrant, stirring so it doesn't burn.

Deglaze and build flavor

If using, pour in 1/2 cup dry red wine to deglaze the pan, scraping up browned bits from the bottom. Let the wine reduce until mostly evaporated, about 2–3 minutes.

Add tomatoes and seasonings

Stir in 2 tablespoons tomato paste and cook 1 minute. Add the crushed tomatoes, 1/2 cup stock, dried basil, dried oregano, bay leaf, sugar, 1 teaspoon salt and 1/2 teaspoon black pepper. Stir to combine and bring the sauce to a gentle simmer.

Simmer with meatballs

Gently nestle the browned meatballs into the simmering sauce. Reduce heat to low, cover partially, and simmer for 25–30 minutes until meatballs are cooked through and sauce has developed flavor. Stir occasionally and spoon sauce over meatballs to ensure even cooking. If sauce thickens too much, add up to 1/4 cup water or stock.

Finish sauce

Taste the sauce and adjust salt and pepper as needed. Remove and discard the bay leaf. If you prefer a smoother sauce, use an immersion blender to gently break down some tomato pieces, but keep texture for a rustic finish.

Pasta & Finish

Cook spaghetti

Bring a large pot of water to a rolling boil and add 1 tablespoon salt. Add 12 ounces spaghetti and cook according to package directions until al dente (usually 8–10 minutes). Reserve 1/2 cup of the pasta cooking water before draining.

Combine pasta and sauce

Add the drained spaghetti directly to the skillet with the sauce and meatballs (or transfer sauce to the pasta pot if easier). Toss gently to coat pasta, adding up to 1/2 cup reserved pasta water as needed to loosen and silky the sauce so it clings to the spaghetti.

Plate and garnish

Divide spaghetti and meatballs among 4 plates or bowls (serves 4). Garnish with torn fresh basil leaves and a generous sprinkle of grated Parmesan. Serve immediately.