1 medium ripe avocado, peeled and chopped, divided
1 tablespoon water
3 teaspoons lime juice, divided
2 teaspoons blackened seasoning, divided
1 teaspoon ground cumin
1 can (15 ounces) black beans, rinsed and drained
1 small navel orange, peeled and chopped
1/4 cup chopped red onion
1 jalapeno pepper, seeded and chopped, optional
1 tablespoon minced fresh cilantro
6 tostada shells
1 cup shredded Mexican cheese blend
1 tablespoon canola oil
1 pound uncooked shrimp, peeled and deveined
Sour Cream, optional
Preheat oven to 350°. In a small bowl, combine 2 tablespoons chopped avocado, water, 1 teaspoon lime juice, 1 teaspoon blackened seasoning and cumin. Set aside 1/4 cup beans; add remaining beans to avocado mixture and mash with a fork. Stir in reserved whole beans. Set aside.
For salsa, in a small bowl, combine orange, onion, jalapeno, cilantro, and the remaining avocado and lime juice. Cover and refrigerate until serving.
Place tostada shells on ungreased baking sheets; spread with bean mixture. Sprinkle with cheese. Bake until bean mixture is heated through and cheese is melted, 4-6 minutes.
Meanwhile, in a large nonstick skillet, heat oil over medium-high heat. Add shrimp and remaining 1 teaspoon blackened seasoning. Cook and stir until shrimp turn pink, 4-6 minutes. Arrange over tostada shells; serve with salsa. If desired, top with sour cream.