This recipe for russian mini hamburgers or kotletki is a popular fast-food dish that is eaten for lunch and dinner. In poland, these are called kotleciki (kawt-let-see-kee), which are miniature versions of kotlety. They can be made with any combination of ground meat, but beef and pork are most popular. Grated potato or bread softened in milk can be used as a binder. If using the former, grate 1 medium peeled potato with the onion and skip the bread and milk.