For the cooking salad, pluck and clean the leaves from the cooking lettuces. Put them in salted and boiling water and cook until the leaves are pithy and soft. Then strain and coarsely chop.
Heat the fat or oil in a saucepan and add the flour. Roast until the flour is golden brown. Then fry the onion and add the parsley.
Mix the soup seasoning with 1/2 l of water and add to the pot. Cook for about 1/4 hour at low temperature. Add the chopped lettuce and season with salt and pepper.