Place Bread Cubes In A 9"X13" Baking Pan (Preferably Glass). Broil Bread Until Golden Brown. Mix The Tahini With Crushed Garlic, Salt, And Lemon Juice. Add Enough Water To This Paste To Bring The Consistency Of Pancake Batter. Drain The Beans, Wash Well. Stir The Beans Into The Tahini Mixture. Spread The Beans Mixture Over The Toasted Bread Cubes. Sprinkle With The Spices Starting With Black Pepper And Ending With Sumac. Melt Butter Until Golden Brown. Stir In Either Cayenne Or Paprika According To Taste. Drizzle Over The Prepared Dish. Serve Immediately.