To make the marinade: whisk together the tomato juice, vinegar, garlic, soy sauce, honey and pepper flakes. Remove and reserve half of the marinade.
Add the pork to the remaining marinade. Cover and marinate at room temp for 30 minutes.
Remove the meat and discard the marinade.
In a nonstick wok or larg skillet over high heat, bring the reserved marinade to a boil. Reduce heat to medium and boil for 2 minutes. Add the pork, cover and cook for 5 minutes. Uncover and continue to cook until the pork is cooked through and the sauce has thickened, about 5 more minutes.