1. Preheat oven to 450°F (224°C).

For the meatballs

1. Heat olive oil in a frying pan. Add leeks and cook until translucent, about 2 minutes. Set aside to cool slightly.
2. In a bowl, combine ½ cup parmesan cheese, plain bread crumbs, salt, milk, Worcestershire sauce, and eggs; mix to blend.
3. Add ground beef and mix to combine using a sturdy spatula or wooden spoon.
4. Scoop out mixture using a one-ounce cookie scoop or ice cream scoop and form 1½ inch meatballs.
5. Place meatballs in an oven-proof skillet or sauté pan. Set aside.

For the tomato sauce

1. In a bowl, mix together crushed tomatoes, diced tomatoes, and tomato paste.
2. Add the tomato mixture to the pan with the meatballs.
3. Transfer the pan to the oven and bake for 20 minutes, or until meatballs are cooked through.
4. Remove from oven and sprinkle with parsley and the remaining ¼ cup grated parmesan cheese.

For the polenta

1. Add milk and stock to a medium saucepan and bring to a boil.
2. Gradually whisk in polenta.
3. Reduce heat to low and cook, stirring frequently, until the mixture thickens, about 20-25 minutes.
4. Turn off the heat and add parmesan cheese.