Flavor Step - Mix all the marinade ingredients together in a bowl and toss the pork strips in the marinade until they are well coated. Marinate for 30 minutes at room temperature.
Heat 1-1/2 teaspoons of the oil in a wok or heavy skillet over the highest heat. Stir-fry the red bell peppers for 2 minutes. Remove and set aside.
Remove the meat from the marinade, saving the marinade.
Add the remaining 1-1/2 teaspoons oil and the meat to the pan and stir-fry until the strips are just cooked through and no longer pink inside, 2 to 3 minutes.
Add the reserved marinade, the fish sauce, green onions or scallions, pineapple, and the peppers and cook, stirring often, until most of the liquid has evaporated and the sauce coats the pork, 1 to 2 minutes.
Spoon the meat and sauce into a bowl, sprinkle with the chopped mint, and serve.