Chicken Feta Meatballs

I found some ground chicken at the store really, really cheap.  So I bought it having no idea what I'd do with it and it sat in my freezer for a few months.  One day I was taking inventory of the freezer and decided it was time to use it, so I made up this recipe and it ended up being really good.

1 lb. ground chicken
1 egg
2/3 cup seasoned bread crumbs
1 1/2 cups fresh mushrooms
2 cloves garlic
1/2 a medium onion
1/2 cup loosely packed spinach
1 cup (approx) Feta Cheese

Mince the onion, garlic and mushrooms.  If you have a food processor or a good blender, throw them in and make them into a paste.  Finely chop the spinach. Mix the meat, egg and bread crumbs.  Add the mushroom, garlic, onion and spinach and mix well.  Take a bit of the meat mixture and flatten.  Put a few feta crumbles in the middle and form into a ball (about golf ball sized).  Cover and bake for 30-45 minutes.