This cake is frequently made during Lent as it contains no animal products. Peanut butter, the smooth, creamy variety, may be used instead of tahini. Oven temperature: 180 C (350 F) Cooking time: 45-60 minutes Grease a 20 cm (8 inch) tube pan or a 20 x 30 cm (8 x 30 cm) slab cake pan with melted margarine or oil. Chill in refrigerator until required. Beat tahini, sugar and orange rind for 10 minutes, then gradually beat in orange juice. Sift dry ingredients twice and fold into tahini mixture. Blend in walnuts and sultanas. Dust chilled cake pan with flour and turn batter into pan. Spread evenly and knock base of pan on table top to settle batter. Bake in a moderate oven for 55-60 minutes for tube pan, 45 minutes or so for slab cake. When cooked, invert cake in its pan onto cake rack and leave for 2-3 minutes before lifting pan from cake. Cool cake and cut in slices or squares to serve. Store cake in a sealed container.