Step 1

Finely grate 1/4 cup Parmesan cheese and place in a large bowl. Finely chop 1/2 small yellow onion and 2 cloves garlic, then coarsely chop 1/4 cup fresh parsley leaves; add everything to the bowl. Add 8 ounces ground beef, 8 ounces ground pork, 1/2 cup panko, 1/3 cup milk, 1 egg, 1 teaspoon kosher salt, 1/2 teaspoon ground oregano, and 1/4 teaspoon ground black pepper. Mix lightly with a fork until just combined.

Step 2

Form the mixture into 1 1/2-inch meatballs (about 2 tablespoons each), wetting your hands with water as needed to keep the mixture from sticking, and place on a baking sheet so that they are not touching. You should have 16 to 18 meatballs.

Step 3

Heat 2 tablespoons olive oil in a 12-inch high-sided sauté pan over medium-high heat until shimmering. Add the meatballs in a single layer and cook until browned on the bottom, about 3 minutes. Flip the meatballs and brown the other side, about 3 minutes more. Transfer to large plate (the meatballs will not be fully cooked).

Step 4

Pour 1/4 cup water into the pan and use a wooden spoon to scrape up any browned bits on the bottom of the pan. Add 1 jar or 3 cups marinara sauce and bring to a simmer. Gently add the meatballs into the sauce, and reduce the heat to simmer gently until the meatballs are cooked through, 5 to 10 minutes.