Bring 1/2 litre of water to the boil, stir in the corn semolina and allow to swell for approx. 20 minutes while stirring continuously. In the meantime, wash the tomatoes and cut them into slices. Peel onions and cut into thin slices.
Wash the parsley and remove the leaves. For the vinaigrette, mix vinegar, 3 tablespoons of water and oil. Season with salt and pepper and mix with the tomatoes, onions and 3/4 of the parsley leaves.
Drain the corn. Stir the corn and egg into the corn semolina. Season to taste with salt, pepper, curry and cumin. Place portions of polenta mass on a greased baking tray with a tablespoon and press them apart with the spoon flat to form a small buffer.
Bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for 20-25 minutes. In the meantime, chop the remaining parsley for the kefir sauce. Mix with kefir and yoghurt and season with salt, pepper and curry.
Arrange tomato salad and corn cobs on plates. Sauce extra will do.