Preheat your oven to 375°F (190°C). In a large mixing bowl, combine ground beef, breadcrumbs, Parmesan cheese, chopped onion, minced garlic, salt, and pepper. Mix until well combined.

Scoop meat mixture and roll into golf ball-sized meatballs, about 1 to 1.5 inches in diameter. Place on a parchment-lined baking sheet.

In a skillet, heat olive oil and brown the meatballs for about 5 minutes until golden brown on all sides. Remove from skillet.

In the same skillet, sauté 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 skillet, deglazing by scraping up any brown bits. Let simmer for about 2-3 minutes.

Add beef broth to the pan, then gently return the meatballs to the skillet. Cover and reduce heat to low; simmer for 30 minutes.

Serve meatballs on plates, drizzled with gravy. Pair with creamy polenta, pasta, or crusty bread.