Preheat oven to 500 degrees.
In a skillet heat vegetable oil over moderately high heat. Add the zucchini, cumin, cayenne, salt and pepper and cook, stirring for 2 to 3 minutes. Add the corn, stirring, and cook for another 2 minutes. Remove from heat and set aside.
In a small bowl stir together ricotta, 1 cup Monterey Jack, oregano, salt and pepper to taste. Put salsa in a fine sieve set over a bowl and drain 3 seconds (do not press on solids). Transfer salsa to another bowl.
Lightly grease a loaf pan, 8 1/2 by 4 1/2 by 3 inches, and trim tortillas with scissors into six 5 by 3 3/4-inch rectangles. Cover bottom of loaf pan with 2 tortillas, overlapping them in middle. Spread 1/4 cup salsa over tortillas and top with half cheese mixture, half zucchini, half peppers, half corn, and 1 tablespoon coriander. Make another layer of tortillas and vegetables in same manner. Top with remaining 2 tortillas, 1/2 cup salsa, 1/4 cup Monterey Jack, and 1 tablespoon coriander. Cover lasagna with foil and bake in middle of oven 12 minutes, or until heated through and cheese is melted. Let lasagna stand, covered, 5 minutes before serving. Cut lasagna in half and serve with lime.