My grandmother was a basic meat and potatoes cook...lots of pot roast, roast beef, and steaks. These meatballs were one of her best recipes, and I enjoy making them for my family and friends. They are always a hit.
Using hands, mix ground beef, ground pork, 3/4 cup Parmesan cheese, 1/2 cup breadcrumbs, egg, shallot, milk, parsley, garlic, 1 teaspoon salt, and 1 teaspoon pepper together in a bowl.
Pinch off and roll mixture into 1 1/2 inch meatballs (about 30 meatballs total).
Spread 1/2 cup breadcrumbs into a shallow dish. Coat meatballs with breadcrumbs, shaking off excess, and transfer to a large plate.
Heat 1 tablespoon oil in a large nonstick skillet over medium heat.
Brown half the meatballs on all sides, 6-8 minutes. Transfer to a paper towel lined plate. Repeat with 1 tablespoon more oil and remaining meatballs. Transfer to plate.
Heat remaining 1 tablespoon oil in skillet over medium heat until shimmering. Add onions and cook until softened, about 5 minutes. Stir in chicken broth and water, then slowly whisk in remaining 1 cup parmesan cheese, and 1/4 cup breadcrumbs until smooth, and bring to a simmer.
Nestle meatballs into skillet and bring to a simmer. Cover, and reduce heat to medium-low, and let simmer 10-15 minutes, or until meatballs are cooked through. If sauce gets too thick, add a little more chicken broth to thin it out.