Meatballs in Stroganoff Sauce

Ingredients

• 1 lb. lean ground beef
• 1 lb. lean ground pork
• 1/2 c. bread crumbs
• 1/2 onion, finely grated with its juices
• 1/2 c. beef stock or milk
• 1 egg, beaten
• 1 t. black pepper
• 2 t. salt
• 1 T. vegetable oil, for frying
• 1 T. vegetable or olive oil
• 1 T. butter
• 1/2 lb. mushrooms, sliced
• 1/2 t. salt
• 1/2 t. black pepper
• 1 onion, sliced
• 2 cloves garlic, minced
• 2 T. flour
• 1/4 c. brandy, dry sherry, or whiskey
• l/2 c. beef stock
• 1 bay leaf
• 1 t. whole grain mustard
• 1 c. full-fat sour cream or creme fraiche
• 1 t. fresh parsley or dill, optional garnish