Slice mushrooms. Chop green pepper. Saute onion, garlic, mushrooms, and pepper. Add beans, tomatoes, spices, and wine. Simmer gently 30 minutes. Preheat oven to 350. Mix ricotta and yogurt. In oiled 1- 0.5-qt casserole, layer tortillas, sauce, cheese, and cheese-yogurt mixture. Repeat until all ingredients are used, ending with layer of sauce. Top with cheese-yogurt mixture and black olives. Bake 15-20 minutes.