Gently mix pork, cornstarch, salt and pepper by hand in a medium bowl.
Heat the oil in a large rimmed skillet over medium heat.
Add pork, beans, and garlic to the skillet. Cook until pork loses is not longer pink and crumbles, about 7-8 minutes. The green beans will brighten in color and start to soften.
While pork cooks, whisk hoisin, sugar, red pepper and soy sauce in a bowl. Pour soy mixture into the pork and green beans. Cook 2-3 minutes to allow sauce to heat and thicken. Serve with rice.