Get rid of the coat ! If the tail comes with. Cut it in 4 pieces. The size doesn´t matter really. It´s important that the tail fits in your pot.
Chop the onions and the vegetable ( if they´re not). Heat the oil in a pot, add the kangaroo tail and the onion and fry until brown. After that add the vegetables, beans, garlic cloves and the potatos and stir for a while. Now add a little bit water, meat had to be covered, and turn heat down. Simmer for 1 1/2 - 2 hours. Now add some seasoning and curry. You can serve it with flat bread (flour, a little bit yeast, salt and oil) or rice.