Peel the potatoes and cook in boiling salted water for about 20 minutes. In the meantime, clean and wash the leek and cut approx. 75 g into very thin rings, the rest into thicker rings. Peel and wash the carrots.
Roughly grate about 100 g, cut the rest into slices. Grate cheese. Drain potatoes, steam and press through a potato ricer. Knead with flour and egg. Knead in thin leek rings, grated carrots, 75 g peas and cheese (keep some for garnishing).
Season with salt if necessary. With floured hands, form 8 flat cakes from the mixture and turn in sunflower seeds. Fry in hot oil for 8-10 minutes, turning until golden brown. Remove from the pan and keep warm.
Sauté the rest of the leek and carrots in the frying fat. Add stock and cream and cook in open pot for 8-10 minutes. Add the remaining peas shortly before the end of the cooking time, season vegetables with salt and pepper.
Arrange vegetables and cakes on a plate, sprinkle with chopped parsley and grated cheese.