Season pork all over with salt and pepper to taste and parsley. In meat grinder or food processor, chop together onions, garlic and pancetta. Cook pork, ground pancetta mixture and olive oil in large casserole, preferably earthenware, covered over very low heat, turning meat only once, until onions begin to color, about 1 hour. Add red wine and cook, stirring occasionally. After about 2 hours, onions will be well-browned and most liquid will be evaporated. Raise heat to medium, add 2 to 3 tablespoons tomato paste and cook, stirring constantly, until tomato paste mixes in and becomes dark brown. Repeat, using 2 to 3 tablespoons at a time, until all tomato paste is used. Add tomato puree and 1/4 cup water, lower heat, cover and cook another two hours, adding water from time to time to keep sauce from drying out. When pork is tender enough that meat fork slides in easily, remove from sauce and set aside. Add sausage and continue cooking sauce one hour more. Sauce should be "dark, unctuous, shiny and thick." Pastry Crust Combine flour and sugar in large mixing bowl and cut in butter. Beat egg yolks and salt until light and add, little at time, until flour mixture just holds together. Divide in two parts, one slightly smaller than other. Gather both into balls, flatten into discs, wrap tightly and refrigerate one hour. PEAS AND MEATBALLS In small bowl, cover mushrooms with hot water. Set aside one hour. In large bowl, combine ground beef, egg, Parmigiano-Reggiano, parsley, salt and pepper to taste and bread crumbs. Form into walnut-sized meatballs. Melt butter in small skillet over medium-high heat and briefly fry chicken liver and heart just until cooked through, about five minutes. Remove and reserve. In large saute pan, cook pancetta and minced onion over low heat until soft, about 10 minutes, then add white wine. Cook until wine evaporates. After 10 minutes, add mushrooms and filtered soaking liquid, tomato paste, cooked chicken liver and heart and meatballs. Simmer for 10 minutes, then set aside to cool. When cool, add peas. ASSEMBLY Season pigeon breasts or chicken with salt and pepper to taste and fry in butter on both sides until brown, three to five minutes. Add finely chopped onion and white wine and cook, covered, until wine evaporates. Cool and cut meat into pieces. Roll out larger pastry ball into large circle and place in 9-inch springform pan. Gently push into corners to cover bottom and sides of pan and leave remainder draped outside. continued in part 2