With its distinctively tart yogurt sauce, this is particularly good served with wheat pilaf.
Saute onion in 1 tablespoon butter until transparent. Cool slightly. Mix with meat, egg, bread, and seasonings. Shape into 1-¼” balls and roll them in dry bread crumbs. Brown slowly in remaining 2 tablespoon butter. Drain off all but 2 tablespoon fat. Gently spoon yogurt over and around meatballs. Simmer for 20 minutes. Serve hot with rice or wheat pilaf. For extra flavor dissolve a bouillon cube in the water used to cook the rice.