-(or more to taste) Chop the onion and mushrooms finely. Saute over low heat in the oil for about 3 minutes, until tenderized. Chop the walnuts coarsely. Grind the sunflower seeds finely. Add all the rest of the ingredients to the onions and mushrooms, and mix well. Transfer to a greased baking dish and bake in a 350 F (180 C)/ Gas Mark 4 oven for about 45 minutes. Serve with Creamy Gravy (see recipe below) if desired and seasonal vegetables. CREAMY GRAVY: Put the oats, water and oil in a liquidizer and blend thoroughly. Pour the mixture into a small saucepan and heat gently, stirring constantly until it has thickened. Stir in the yeast extract. If the mixture is too thick add a little more water. (N.B. This can be made earlier and reheated when serving the roast.)