Shrimp Tostadas with Lime-Cilantro Sauce

Shrimp Tostadas with Lime-Cilantro Sauce 1-1/2 pounds peeled and deveined cooked shrimp (26-30 per pound), coarsely chopped 1-1/2 cups chopped, peeled English cucumber 8 radishes, thinly sliced 4 plum tomatoes, chopped 4 green onions, chopped 2 jalapeno peppers, seeded and minced 2 tablespoons minced fresh cilantro 2 tablespoons lime juice 3 garlic cloves, minced 1 teaspoon salt 1/4 teaspoon pepper 1 medium ripe avocado, peeled and cubed SAUCE: 1 cup sour cream 2 tablespoons minced fresh cilantro 1 teaspoon grated lime zest 1 tablespoon lime juice 1/4 teaspoon salt 1/4 teaspoon ground cumin 1/8 teaspoon pepper ASSEMBLY: 10 tostada shells Place first 11 ingredients in a large bowl; toss to combine. Gently stir in avocado; let stand 15 minutes. In a small bowl, mix sauce ingredients. To serve, spread tostada shells with sauce. Top with shrimp mixture.