Instructions:
Preheat oven to 400º F.

In a medium bowl, marinate shrimp in ¼ cup lime juice, salt and garlic. Refrigerate for 15-20 minutes. Drain and set aside. In a medium bowl, combine red onions, black beans, corn and cumin. Set aside. In a small bowl stir together sour cream and 1 tablespoon lime juice. In a medium skillet, heat oil over medium heat. Add shrimp and cook, stirring frequently until they begin to turn pink, about one minute. Remove from heat.  In a 9 x 13 inch shallow baking pan or ovenproof platter, arrange half of the chips in a single layer. Top with half of each of the cheeses, the bean mixture and shrimp. Repeat with the remaining chips, bean mixture and shrimp. Top with remaining cheese. Bake for 10 minutes until the cheese is melted. Remove from oven and dollop with sour cream mixture. Sprinkle top with cilantro and tomatoes. Serve immediately.  

Serves 4-6