How to Make It
Heat a large frying pan over moderate heat. Add the sesame seeds and cook, stirring frequently, until browned, 2 to 3 minutes. Remove the seeds from the pan immediately.
In a blender, combine the vinegar, ginger, garlic, orange juice, sesame oil, the 1/3 cup cooking oil, 1/4 teaspoon of the salt, and 1 tablespoon of the toasted sesame seeds. Puree until smooth and leave the dressing in the blender.
In the frying pan, heat the remaining 1 tablespoon oil over moderate heat. Season the chicken breasts with the remaining 1/4 teaspoon salt and the black pepper and add to the pan. Cook until brown, about 5 minutes. Turn and cook until almost done, about 3 minutes more. Cover the pan, remove from the heat, and let steam for 5 minutes. Remove the chicken from the pan. Set the pan over moderate heat and add the water. Cook, scraping the bottom of the pan to dislodge any brown bits, until reduced to 1 tablespoon. Transfer the liquid to the blender and pulse to combine. When the chicken breasts are cool enough to handle, cut them into bite-size pieces and toss with the remaining sesame seeds.
In a large bowl, toss the spinach with the red-pepper strips and the chicken. Serve the salad with the dressing spooned over the top.