Pastitsio

Make the sauce: In a large deep skillet, heat olive oil over medium heat. Add onions, and cook until they begin to soften, about 3 minutes. Add lamb, salt, cinnamon, pepper, and nutmeg. Cook, breaking lamb into pieces, until it is no longer pink. Add wine, and cook until liquid is almost evaporated. Stir in tomato paste, bay leaves, and 2 cups water. Cover, and let simmer 30 minutes, skimming the fat occasionally. Remove from heat, and set aside, covered.

Make the bechamel: In a large saucepan, melt butter over medium heat. When butter is bubbling, add flour and baking powder. Cook, stirring constantly with a wire whisk, for 1 minute. While whisking, slowly pour in milk. Continue cooking, whisking constantly, until the mixture bubbles and becomes thick. Remove pan from heat, and stir in Parmesan, salt, black pepper, nutmeg, and cayenne pepper. Set aside, covered, until ready to assemble.