In a large pot, heat 2 tbsp. sesame oil over medium. Add the garlic; cook, stirring often, until softened, about 2 minutes. Add the stock, ponzu sauce, soy sauce, ginger, crushed red pepper and star anise; bring to a boil.
Reduce the heat to medium-low and stir in the soba noodles and bok choy. Cook until the noodles are tender, 3 to 4 minutes.
Discard the star anise pods and divide the soup among bowls. Drizzle each serving with 1 tbsp. sesame oil. Top with the shredded carrot and sesame seeds.