Whisk together the orange juice, soy sauce, hot pepper sauce, cilantro, garlic, brown sugar, peanut butter, and ginger root in a bowl. Lie the tenderloins in a glass baking dish; pour the orange juice mixture over the tenderloins. Marinate in refrigerator at least 1 hour and up to 8 hours or overnight.
Preheat an oven to 375 degrees F (190 degrees C). Line a baking sheet with aluminum foil.
Transfer the tenderloins to the foil-lined baking sheet, reserving the marinade.
Cook until the pork is no longer pink in the center, 30 to 35 minutes. An instant-read thermometer inserted into the center should read 145 degrees F (63 degrees C).
While the pork cooks, combine the reserve marinade and chicken stock in a saucepan. Bring to a boil. Allow to boil 2 minutes; reduce heat to low and simmer 5 to 7 minutes. Cut the tenderloins into 1/4-inch slices; spoon the sauce over the sliced pork to serve.
