Place the fresh breadcrumbs in a small bowl and pour the milk over them; let soak for 5 minutes until the crumbs are soft. Meanwhile mince the garlic and finely grate or mince the onion. Finely chop the parsley.

Mix meatball ingredients

In a large bowl combine the ground beef and ground pork. Add the soaked breadcrumbs (including any excess milk), egg, grated Parmesan, chopped parsley, minced garlic, grated onion, salt, black pepper, dried oregano, and red pepper flakes if using. Use clean hands to gently mix until just combined; avoid overworking to keep meatballs tender (mix about 30-40 strokes).

Form meatballs

Portion the mixture into roughly 1 1/4-inch meatballs (about 1.5 oz / 42 g each) using a spoon or a small ice-cream scoop. Roll gently between your palms to form smooth spheres. Place formed meatballs on a rimmed baking sheet lined with parchment or wax paper.

Brown meatballs

Heat 2 tablespoons olive oil in a large skillet over medium-high heat. When oil is shimmering, add meatballs in a single layer without crowding (work in batches if needed). Cook, turning occasionally, until browned on all sides, about 6-8 minutes total. They do not need to be fully cooked through at this stage. Transfer browned meatballs to a plate.

Tomato sauce (quick)

Start sauce

In the same skillet (wipe out excess fat if more than a tablespoon remains, leaving about 1 tablespoon) reduce heat to medium and add 1 tablespoon olive oil. Add sliced garlic and cook 30-60 seconds until fragrant but not browned.

Add tomatoes and simmer

Pour in the crushed tomatoes and stir in the tomato paste. Add sugar if using, 3/4 teaspoon salt, and 1/4 teaspoon black pepper. Bring to a gentle simmer, then reduce heat to low.

Finish meatballs in sauce

Nestle the browned meatballs into the simmering sauce. Cover the skillet partially and let simmer gently for 15-20 minutes, turning the meatballs once halfway through, until cooked through (internal temperature 160°F / 71°C) and sauce has thickened slightly. Taste and adjust salt/pepper. Stir in torn basil leaves in the last 2 minutes of cooking.

To serve

Cook pasta

While the meatballs simmer, bring a large pot of salted water to a boil and cook pasta according to package directions until al dente. Drain, reserving 1/2 cup pasta cooking water.

Combine and serve

If desired, toss the drained pasta with a few tablespoons of the tomato sauce and a splash of reserved pasta water to help the sauce cling. Plate pasta, top with meatballs and extra sauce. Garnish with fresh basil leaves and grated Parmesan. Serve immediately.