In a large mixing bowl combine minced meat, egg, salt, and crumbs. Add diced onion and mushrooms.
Rinse your hands in cold water and form the meatballs using your fingers or a cookie scoop.
Heat up the pan with olive oil, add meatballs and cook for 4 minutes on each side until golden brown.
Take from heat and set aside.
Add finely chopped or minced garlic to the pan, cook for 1 minute constantly stirring.
Add crushed tomatoes, oregano, pepper, and stir well.
Cook the mixture for few minutes, stir in the sour cream.
Return meatballs to the pan and coat evenly with sauce. Cook on reduced heat for 15 minutes.
Serve with fresh parsley, parmesan (optional) and pasta, rice, or your favorite side dish.