Whisk chicken broth, soy sauce, balsamic vinegar, 1 T. of the cornstarch, the sesame oil and sugar in a measuring cup. In a large bowl, toss chicken with 3/4 t. salt and a few generous grinds of pepper. Add remaining 1/4 cup cornstarch and toss with the chicken. You may want to use tongs as the cornstarch has a chalky texture, shaking off excess cornstarch. Heat 3 T. of canola oil in large (12 inch) heavy skillet over medium high heat until it's simmering hot. Sauté chicken, flipping after 2 minutes, until lightly browned on two sides, about 4 minutes total. It's all right if the chicken sticks slightly and if the sides of the chicken are still raw. Add the remaining 1 T. canola oil to skillet. Add chiles and their seeds, the ginger and whites of the scallions and cook, stirring, for 1 minute. Add red pepper and celery and cook, stirring until softened slightly, about 2 minutes. Add sherry and cook until it almost completely reduces, 30 to 60 seconds. Scrape the bottom of the pan to incorporate any browned bits. Give the chicken broth mixture a quick whisk, stir it into the chicken and vegetables and bring to a boil. The sauce should immediately thicken. Slice into one of the chicken pieces to see if it's cooked through. If still pink, reduce to a simmer, cover and cook for another few minutes. Serve at once, sprinkled with peanuts and the scallion greens.