Soba Noodle Soup With Chicken and Bok Choy

Name: Soba Noodle Soup With Chicken and Bok Choy
Ingredients: 8 cups chicken stock , or low-sodium chicken broth; 1 boneless, skinless chicken breast (about 12 ounces ); 1 (2-inch) piece fresh ginger , finely chopped (about 2 tablespoons); 1/4 cup lime juice; 2 tablespoons Thai fish sauce; 3 tablespoons Thai sweet red chili sauce; 1 tablespoon brown sugar; 8 ounces soba ( buckwheat) noodles; 4 baby bok choy , cut into 1-inch slices or halved lengthwise; 6 scallions , thinly sliced; Few sprigs Thai basil, mint, or cilantro , for garnish; Lime wedges , to serve; Red pepper flakes , for garnish