Meatballs with Tomato Sauce (Polpette al sugo)

Ingredients

• 1/2 pound of ground pork
• 1/2 pound of ground veal
• 1/2 pound of ground beef
• 1 cup of chopped parsley
• 1 large egg
• 1/4 cup of milk
• 1/2 cup of grated Grana Padano or Parmigiano Reggiano
• Kosher salt and freshly ground black pepper to taste
• 1/2 cup of unseasoned breadcrumbs
• 1/2 medium sized red onion finely diced
• 1-2 pieces of garlic finely diced
• 1/2 cup of Canola oil for pan frying