Peel the kohlrabi and cut into thin slices. Peel and chop onion and garlic. Wash the tomatoes, cut into quarters, remove seeds and dice. Heat oil and fry onion, garlic, peppercorns and curcuma over medium heat. Add kohlrabi slices, sauté briefly, then deglaze with water. Simmer firm to the bite. Mix tomatoes with the hot turnip vegetables and season with salt.
Mix beef with egg and breadcrumbs. Season well with salt and pepper. Form small balls and fry over low heat until golden brown.