1.  Preheat broiler.  Whisk together oil and 1-1/2 teaspoons cumin in a small bowl; salt to taste.  Lightly brush both sides of each tortilla with cumin oil and arrange in a single layer on a cookie sheet.  Broil 4 inches from heat, turning once, until golden brown and crisp, about 2 minutes.  Transfer to rack to cool. 

5.  Arrange bowls of chicken beans, and stack of tortillas on the table.  Place lettuce, salsa, and sour cream in separate bowls; serve on the side .  Top each tortilla with desired toppings to create individual salad tostadas.  Makes 4 servings.