In a small bowl, stir together orange peel, orange juice, soy sauce, garlic, thyme, paprika, black pepper, and crushed red pepper; set aside.
Cut each chicken breast half crosswise in half. Place each piece between two pieces or plastic wrap. Using the flat side of a meat mallet, pound the chicken lightly to about 1/4 inch thick. Remove plastic wrap.
In a very large nonstick skillet heat the oil over medium-high heat. Cook chicken in hot oil for 4 minutes, turning once. Carefully add orange juice mixture to skillet. Simmer for 3 minutes or until liquid reduces to a glaze, turning to coat chicken.
Place chutney in a small bowl; snip any large pieces of fruit. Stir in mayonnaise. To assemble sandwiches, spread mayonnaise mixture on cut sides of toasted sandwich thins. For each sandwich, place 1/2 cup of the watercress and a chicken portion on bottom half of sandwich thin. Add sandwich thin top, spread side down.
3 lean protein, 1 1/2 starch, 1/2 fruit