Peel, wash and roughly grate the carrots and potatoes. Mix carrots, potatoes, egg and starch, season with salt and pepper. Wash the chives, shake dry, cut into small rolls and fold into the roasting mixture.
Heat the oil in portions in a coated pan. Shape the mixture into 4 roasts and fry on both sides for about 10 minutes.
Zucchini wash, clean, cut into thin slices and season with salt. Heat olive oil in a pan. Fry the zucchini briefly while turning. Wash and clean the tomatoes and cut them horizontally from the middle into 4 thick slices.
Clean, wash and shake dry the rocket. Wash lemon hot, rub dry, peel in zests. Halve the lemon, squeeze one half. Mix sour cream with lemon zests, juice and milk.
Season to taste with sugar, salt and pepper.
Cover each tomato slice with a roast, slices of zucchini and rocket. Drizzle lemon sauce over it. Add the rest of the sauce.