In a mixing bowl, combine tuna and 1 teaspoon of the TABASCO® Sauce; mix well. Add tomato, onion, cilantro, sour cream, lime juice and 1/4 teaspoon of the salt. Toss well. Cover and chill.
With a spoon, scoop avocados into a medium bowl and mash them with a fork; add remaining 1/2 teaspoon salt and 1/2 teaspoon TABASCO® Sauce, mixing well. Set aside.
Preheat oven to 350°F. Spray tortillas lightly on both sides with vegetable cooking spray. Place in a single layer on a baking sheet. Bake until crisp, about 10 to 12 minutes. Cool. To assemble, spread one rounded tablespoon avocado mixture on each baked tortilla. Spread 1/3 cup tuna mixture over avocado. Top each tostada with crumbled cheese and serve.
Makes 8 servings.
*Store-bought tostada shells may be substituted.
Note: Tuna mixture makes a delicious sandwich, using avocado mixture as a sandwich spread.