To make the Chilaquiles, cut the tortillas into ½" wide strips and then stale them on a baking sheet in a low (300°) oven until stiffened.
Simmer the pork with ½ cup onion, 1 clove garlic and the salt in water to cover until tender (30-40 minutes). Cool in the water. Strain the water (reserve) and shred the meat.
Toast the chiles briefly in a dry skillet. Stem and seed the chiles then soak in hot water for 20 minutes to soften. Purée the chiles with the remaining onion and garlic. Sauté this mixture in 2 teaspoons of the olive oil for 2-3 minutes. Purée the tomato with the spices and add to the chile mixture for 2-3 minutes.
Thin with the reserved liquid to sauce consistency.
Sauté the mushrooms in the remaining teaspoon of oil.
In a large bowl combine the tortilla strips, the pork, the chile sauce, raisins, squash, mushrooms and cheese. Transfer to a casserole dish and bake at 350° for 25-30 minutes.
To make the Papaya Relish, combine all ingredients, and then chill.