Chicken (or Shrimp) Tostadas

Name: Chicken (or Shrimp) Tostadas
Ingredients: 10 oz. chicken breast (or shrimp); 1 tsp taco seasoning (reduced sodium); salt (pinch); pepper (pinch); 1 tsp olive oil; 4 corn tortillas; 1/2 cup refried beans; 1/2 cup Mexican cheese (shredded); 1/2 cup shredded lettuce; 1/2 cup pico de gallo; 1/4 cup hot sauce or taco sauce; Guacamole (optional, about 1 tbsp each)