To make the sauce, pour oil in a frying pan, add the meat and 1 of the sliced onions. Cook until the onions turn yellow.
Add the spices, tomato, beans and 1/2 cup of water. Cook for 2 hours on low heat. Add some water if necessary. Keep turning the mixture from time to time.
Cut the 3 remaining onions in thin, round sizes and put them in a separate saucepan on low heat. Cook them until they turn yellow. Add butter and a little salt, chili or pepper. Cook until onions are soft.
Add the 3 cooked onions to the main sauce while the sauce is cooking.
Boil/steam couscous separately, adding oil and salt to taste.