Place the fresh breadcrumbs in a small bowl and pour the milk over them. Stir and let sit for 5 minutes until the milk is absorbed and the crumbs are soft.

Combine ingredients

In a large bowl, add the ground beef, ground pork, soaked breadcrumbs (including any remaining milk), beaten egg, grated Parmesan, minced parsley, minced garlic, kosher salt, black pepper, dried oregano, and red pepper flakes (if using).

Mix gently

Using your hands or a spoon, gently combine the ingredients until just incorporated. Avoid overworking — mix only until evenly combined to keep meatballs tender.

Form meatballs

Portion the mixture into roughly 1-ounce (about 2 tablespoon) portions to make small side meatballs. Roll each portion between your palms to form smooth, compact meatballs. You should get about 24 meatballs.

Finish & cooking

Heat pan

Heat a large nonstick or heavy skillet over medium heat. Add the olive oil and butter and let the butter melt and foam but not brown.

Brown meatballs

Working in batches (do not overcrowd the pan), add the meatballs in a single layer and cook undisturbed for 2–3 minutes to brown the bottoms. Gently roll them to brown other sides, cooking a total of about 6–8 minutes per batch until nicely browned on all sides. Transfer browned meatballs to a plate.

Simmer in sauce

If serving with tomato sauce: reduce heat to low, pour 1 cup of tomato sauce into the skillet and nestle the browned meatballs into the sauce. Cover and simmer gently for 8–10 minutes, until meatballs are cooked through (internal temperature 160°F/71°C for pork/beef mixture) and heated through. If you prefer dry meatballs, return all batches to the pan, add a splash of water (1–2 tbs), cover, and cook over low heat 6–8 minutes until cooked through.

Finish and serve

Remove the lid, spoon sauce over the meatballs, sprinkle with fresh basil and extra grated Parmesan. Taste and adjust seasoning with a pinch of salt and pepper if needed. Serve warm as a side.