Sichuan-Style Chicken Salad (Bang Bang Ji Si)

FOR THE CHICKEN: Cover chicken with plastic wrap and pound thick ends gently with meat pounder until ¾ inch thick. Discard plastic wrap. Whisk 4 quarts cool water with 2 tablespoons salt in Dutch oven. Arrange chicken in steamer basket, making sure not to overlap. Submerge steamer basket in pot. Heat over medium heat, stirring occasionally to even out hot spots, until water registers 175 degrees, 15 to 20 minutes. Turn off heat, cover pot, remove pot from burner, and let stand until chicken registers 160 degrees, 17 to 22 minutes.

FOR THE DRESSING: While chicken cooks, combine vegetable oil, garlic, and ginger in bowl. Microwave until oil is hot and bubbling, about 2 minutes. Stir in chili powder and let cool for 10 minutes.

Strain oil mixture through fine-mesh strainer into large bowl; discard solids. Whisk soy sauce, vinegar, sesame oil, 1 teaspoon peppercorns, and sugar into strained oil. Add up to 1 teaspoon additional peppercorns to taste.

Transfer chicken to cutting board and let cool for 10 to 15 minutes. Shred chicken lengthwise into long, thin strips. Add chicken to bowl with dressing and toss to coat. Season with salt to taste.

FOR THE SALAD: Toss cabbage, 1 cup cilantro, two-thirds of scallions, celery, and pinch salt in second large bowl. Arrange cabbage mixture in even layer on large platter. Mound chicken on top of cabbage mixture and sprinkle with remaining ½ cup cilantro, remaining scallions, and sesame seeds, if using. Serve.