Shred the cauliflower into florets and boil them in salted water. Drain them. Heat the oil and fry the flour.
While stirring constantly with a whisk, pour in some of the cauliflower water and make a sauce of the desired consistency. Season it with freshly ground black pepper, crushed garlic and salt.
Pour thus prepared white sauce over the cauliflower in plates. Optionally, you can arrange the cauliflower in a greased tray, then pour on the sauce and bake them briefly in a hot oven. Serve with fresh chopped dill or parsley.