Cut tenderloin into slices about 1/4 in. thick. Cut each slice into 3 strips. Set aside.
Heat oil and sauté onion until soft, around 5 minutes.
Add garlic and stir for another 1 minute.
Add the rest of the ingredients, except tenderloin and simmer for 5 minutes.
Add pork and simmer until cooked through, about 8 minutes.
Remove pork and put in a bowl.
Boil the sauce until slightly thickened, about 3 minutes. Pour over pork and either freeze or serve as suggested above.