Cook noodles according to package directions. Drain and rinse under cold water. Set aside.

Heat 1 tablespoon oil in a large wok or skillet over high heat. Add bok choy whites cooking and stirring, for 1 minute. Add bok choy greens; cook until wilted, about 1 minute more. Transfer all the bok choy to a medium bowl and set aside.

Add the remaining 1 tablespoon oil, scallion whites, ginger, garlic, sweet chili sauce, and chili paste to the pan. Add ground chicken and cook until no longer pink, 3 to 5 minutes.

Add stock, soy sauce, and sugar. Mix cornstarch and water in a small bowl and add to the pan. Bring mixture to a boil and cook, stirring, until slightly thickened, about 1 minute.

Stir in the reserved rice noodles and bok choy; cook, stirring until heated through, and coated with sauce, about 1 minute. Serve topped with scallion greens and crushed red pepper, if desired.