Oven: Pre-heat to 375F (190C)
Put the oatmeal in a bowl and cover with water. Let it stand for at least an hour. Drain thoroughly.
Place the lentils in a pan of water and boil rapidly for 20 - 30 minutes or until soft (the time will vary according to the type of lentils). When the lentils are ready, drain and rinse them in a sieve.
Saut�e the onion in the oil until it is soft. Add the carrots and mushrooms, and cook for a little longer. Then add the spices, soy sauce, cooked lentils and about a quarter of the kidney beans.
Using a food processor or blender, pur�e the remainder of the beans to form a thick paste (add a little water if necessary to prevent it getting too stiff). Add this to the lentil and vegetable mixture.
Finally, add the drained oatmeal, salt and pepper, and the garlic. If the mixture looks too dry, add the margarine. Mix well.
Transfer to an oven-proof dish and bake for 30 to 40 minutes.