Preheat the oven to 400 degrees while you are preparing your ingredients. Take a pan for the casserole and grease it. Keep it at a side while we prepare the delicious meatballs.

In a pan or skillet add olive oil and sauté the onions. Make sure they are not too brown so cook them on medium heat.

Take a bowl and add ground beef, breadcrumbs, and all the other ingredients except tomato sauce and cheese. Now add the sauteed onions and mix them well.

You can use a scoop now or make meatballs from hand if you have experience. The shapes should be similar for your casserole dish to achieve the perfect look.

Now, bake the meatballs for 15 to 20 minutes.

Get the tray out and clean the excessive oil.

Add tomato sauce and cheese (lots of it) to the meatballs. Bake for additional 5 minutes or more until the cheese is fully cooked.