In a large bowl combine the ground beef, breadcrumbs, milk, egg, grated Parmesan, chopped parsley, minced garlic, grated onion, salt, black pepper, and dried oregano. Mix gently with your hands or a spoon until just combined — avoid overworking to keep meatballs tender.

Portion

Using a small ice cream scoop or tablespoon, portion the mixture into roughly 1-inch (about 20–24) mini meatballs. Roll each portion lightly between your palms to form compact balls; avoid packing too tightly.

Sear meatballs

Heat 2 tablespoons olive oil in a large nonstick or stainless-steel skillet over medium-high heat. Working in batches (do not overcrowd), add meatballs and cook, turning gently, until browned on all sides, about 5–6 minutes total per batch. They do not need to be fully cooked through at this stage. Transfer browned meatballs to a plate lined with paper towel.

Tomato sauce

Sauté aromatics

In the same skillet, reduce heat to medium and add 1 tablespoon olive oil if pan is dry. Add the chopped onion and sauté until translucent, about 3–4 minutes. Add the garlic and cook until fragrant, about 30 seconds.

Build sauce

Stir in the crushed tomatoes and tomato paste (if using). Add chopped basil, sugar, salt, and black pepper. Bring the sauce to a gentle simmer, scraping up any browned bits from the pan for flavor.

Simmer with meatballs

Return the browned meatballs to the skillet, nestling them into the sauce. Reduce heat to low, cover partially, and simmer gently for 12–15 minutes until meatballs are cooked through (internal temperature 160°F / 71°C) and sauce has slightly thickened. Stir gently once or twice so meatballs cook evenly and don't stick.

To finish & serve

Taste the sauce and adjust seasoning with extra salt, pepper or a pinch more sugar if needed. Sprinkle chopped parsley and grated Parmesan over the meatballs.

Serve the mini meatballs hot as a starter: transfer to a warm serving dish, garnish with extra basil or parsley, and provide toothpicks or crusty bread for guests to enjoy.