• Preheat oven to 450°F (224°C).

For the meatballs

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

For the tomato sauce

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

For the polenta

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