Blackened chicken mini tacos

4 medium skinless, boneless chicken breast halves (about 1 pound)
4 teaspoons ground black pepper
4 teaspoons paprika
3/4 teaspoon dry mustard
3/4 teaspoon ground red pepper
1/4 teaspoon salt
24 mini taco shells
Finely shredded spinach or lettuce
Shredded cheddar or Monterey Jack cheese
Dairy sour cream or guacamole
2 ripe medium tomatoes, peeled and finely chopped
2 tablespoons finely chopped red onion
2 tablespoons snipped fresh cilantro
1/8 teaspoon salt
Dash sugar

1. For Pico de Gallo: Combine tomatoes, red onion; cilantro; 1/8 teaspoon salt, and the sugar. Mix well. Cover; chill for several hours or overnight.
2. Cut chicken breast halves into 3/4-inch-wide strips. Combine black pepper, paprika, dry mustard, red pepper, and 1/4 teaspoon salt in a plastic bag. Add chicken to the bag, shaking to coat. Arrange coated chicken in a single layer in a shallow baking pan. Bake, uncovered, in a 350 degrees F oven for 15 to 20 minutes or until chicken is tender and no longer pink. Using two forks, pull chicken apart into pieces.
3. To crisp taco shells, arrange on a baking sheet and bake 5 to 7 minutes or until warm and crisp. Serve chicken in taco shells. Top tacos with Pico de Gallo, spinach or lettuce, cheddar or Monterey Jack Cheese, and sour cream and/or guacamole.