In a large skillet, heat oil over medium-high heat and swirl to coat pan.
Add garlic, ginger, and crushed red bell pepper cooking for about 30 seconds.
Add the bok choy and cook for 3 minutes, stirring often.
Stir in the broth, soy sauce, sugar, and cornstarch and bring to a boil, stirring constantly.
Cook until thickened, about 1 minute.
Remove from heat and sprinkle with sesame seeds.