4 chicken breast halves, skinned, boned, the long triangular fillets removed and reserved for another use, lightly pounded to 1/4-inch thickness
1/4 tsp. salt
1/2 tsp. crushed Sichuan peppercorns, or 1/4 tsp. crushed black peppercorns
3 scallions, blanched for 30 seconds, drained, cooled, patted dry, and halved lengthwise
1 cucumber, peeled, halved lengthwise, seeded, cut into 1/4-inch wide strips, blanched for 30 seconds, drained, cooled, and patted dry
1 sweet red pepper, seeded, deribbed, but into 1/2-inch strips, blanched for 2 minutes, drained and patted dry
2 tbsp. safflower oil

MIRIN SAUCE:

3 tbsp. low sodium soy sauce
1 tbsp. sugar
2 tbsp. mirin, or 2 tbsp. dry sherry
2 tsp. rice vinegar
1/2 tsp. crushed Sichuan peppercorns, or 1/4 tsp. crushed black peppercorns

To prepare the sauce, combine the soy sauce, sugar, mirin or sherry, vinegar, crushed peppercorns and 2 tablespoons of water in a small bowl. Set aside. Sprinkle the chicken with the salt and crushed peppercorns. Cut the scallions, cucumber strips and pepper strips to fit inside the breast halves. Arrange some scallions, 2 or 3 cucumber strips, and 2 or 3 pepper strips across the grain of the meat at the wide edge of each cutlet.

Roll the chicken around the vegetables and fasten each roll lengthwise with a small skewer. Heat the oil in a heavy-bottomed skillet over medium heat and gently saute the rolls, turning them, until golden--about 4 minutes.

Remove the chicken and pour the sauce into the skillet, stirring, being sure to scrape up any brown bits from the bottom. Return the chicken to the skillet; cover loosely, and simmer for 8 minutes, turning once. Transfer the chicken to a heated platter and remove the skewers. Pour the sauce over the rolls and serve immediately.