Preparation:

Pre-heat medium skillet to medium-high. Add nonstick spray and chicken. Season chicken with seasoned salt and cook until done, about 7 minutes each side. Remove, dice chicken into 1-inch pieces, and let cool. 

In small bowl, whisk lime juice, orange juice, olive oil, and crushed red pepper. Add cilantro until just mixed. Fold avocadoes, papaya, tomatoes, and chicken into mixed greens. Add lime juice mixture, mixing until thoroughly coated. Arrange each tostada in a medium bowl. Place half the salad mixture in each tostada. Season with salt and pepper to taste.