Wash, peel and dice the potatoes, carrots and kohlrabi approx. 1 cm in size. Cook in salted water for about 13-15 minutes. Just before the end of the cooking time, add the peas and cook them briefly. Drain the vegetables. Knead the butter and flour together thoroughly. Bring the milk to the boil and stir in the flour butter in small pieces and season with a pinch of nutmeg. Add the vegetables and season with salt and pepper. Stir the chopped parsley into the stew and serve.
Tip: Mixing milk and flour butter with a hand blender is easier.