Cut the pork into thin slices about ⅛ inch thick.
In a medium mixing bowl, whisk together the soy sauce, rice vinegar, garlic, ginger, sesame oil, brown sugar and black pepper.
Place the pork medallions in a big zip-lock and add about ½ cup of the sauce mixture into the bag. Shake and put in the fridge for at least 30 minutes. Reserve the remaining sauce for drizzle.
Place the grill pan on the stove, lightly brush with oil and turn the heat to high heat.
Add all the meat to the pan. Cook and stir constantly until cooked through.
Remove the meat from heat, chop into smaller pieces before serving on warmed Mission Organics Tortillas.
Top your tacos with fresh ingredients: mango, lime, jalapeno, red cabbage, and cilantro.
To make a sauce: Place the reserved sauce (clean marinade sauce) in a saucepan and cook over medium heat, keep stirring occasionally, until the sauce is thick. Reserve to drizzle on tacos.