Mozzarella Stuffed Wagu Meatballs

For reasons unknown my husband purchased a pound of Wagu Beef along with our Grass Fed Beef from our local butcher.  I have never tried Wagu Beef before and had no real idea what to do with it. It seems like a fattier version of ground beef. I decided to make Meatballs and added pound of grass fed beef to the Wagu.  I made both small poached meatballs and also roasted meatballs.  I did a somewhat generic recipe so I could use them in multiple recipes.

1/2 cup milk (whole, 2%, or skim)
1/2 cup fine breadcrumbs (I used some leftover french bread)
1 large egg 
1 teaspoon salt
Freshly ground black pepper
1/2 cup grated Parmesan cheese
1/2 tsp garlic powder
1/4 tsp Cayenne
1 pound ground hamburger and 1 pound ground Wagu or 2 pounds regular hamburger (you can add pork or whatever you like)
1/2 cup finely chopped onion (or grated on a coarse grater) from 1 small yellow onion
4 cloves garlic, finely minced
(I put the onion and garlic in the food processor which turned into a mush like consistency)
Fresh Mozzarella

Combine the milk and breadcrumbs: Pour the milk over the breadcrumbs in a small bowl and set aside while preparing the rest of the meatball mix. The breadcrumbs will absorb the milk and become soggy.

Whisk the egg, salt, pepper, Parmesan, and other spices.

Add the meat to the egg mixture, add the onions and soaked breadcrumbs

Pinch off a piece of the meat mixture and gently flatten, add your cheese and form the meat around the cheese, sealing well. Continue shaping until all the meat is used.

To roast the meatballs in the oven: Arrange the meatballs spaced slightly apart on a baking sheet. bake at 400°F for 25 to 30 minutes. (Watch closely if cooking meatballs made with lean meat.) The meatballs are done when cooked through and the outsides are browned, and when they register 165°F in the middle on an instant read thermometer. 

Freezing cooked meatballs: Let the cooked meatballs cool completely, then transfer to a freezer container or bag. Freeze for up to 2 months. Frozen meatballs can be thawed overnight or reheated directly from the freezer. Reheat meatballs in a simmering sauce for 10 to 15 minutes or in a warm oven for 10 to 15 minutes.