Preheat your oven to 375°F (190°C) to ensure a hot environment for baking. In a large mixing bowl, combine ground beef, breadcrumbs, Parmesan cheese, chopped onion, minced garlic, salt, and pepper.

With clean hands, scoop a generous amount of the meat mixture and roll it into golf ball-sized meatballs, about 1 to 1.5 inches in diameter.

In a large skillet over medium heat, pour in a tablespoon of olive oil and add the meatballs in batches. Sear for about 5 minutes until evenly golden brown on all sides.

In the same skillet, add more olive oil if needed and sauté the chopped onion until translucent, about 3-4 minutes. Stir in minced garlic and tomato paste, cooking until fragrant.

Pour the dry red wine into the pan and scrape up any brown bits on the bottom. Let it simmer for 2-3 minutes to enhance its taste.

Gently return the browned meatballs to the skillet, cover the pan, and reduce heat to low, allowing everything to simmer together for 30 minutes.

After simmering, place the meatballs on serving plates, drizzling them with the rich gravy. Pair with creamy polenta, pasta, or crusty bread.