Preheat your oven to 400°F (200°C).
In a large mixing bowl, combine ground beef, ground pork, breadcrumbs, Parmesan cheese, parsley, egg, garlic, salt, and pepper. Mix until just combined.
Form the mixture into small meatballs, about the size of a golf ball, and place them on a baking sheet.
Bake the meatballs in the preheated oven for 15-20 minutes or until cooked through (internal temperature should reach 160°F/70°C).
While the meatballs are baking, heat olive oil in a skillet over medium heat. Sauté the diced onion until translucent, about 5 minutes.
Add beef broth, Worcestershire sauce, garlic powder, onion powder, and thyme to the skillet. Stir and bring to a simmer.
Once meatballs are cooked, transfer them to the skillet with the gravy. Let them simmer for an additional 10 minutes to absorb the flavors.
If a thicker gravy is desired, stir in the cornstarch mixture and cook until it thickens, about 2-3 minutes.
Serve the smothered meatballs over rice, mashed potatoes, or noodles for a satisfying meal.