2 tablespoons olive oil
2 pounds pork tenderloin
1/2 cup teriyaki sauce
1 cup chicken broth
1/4 cup brown sugar
4 cloves garlic, chopped
3 fresh red chile pepper, finely chopped
1/2 large onion, sliced
1/4 teaspoon black pepper

Heat the olive oil in a skillet over medium-high heat. Brown tenderloins on all sides, about 10 minutes. Meanwhile, mix together teriyaki sauce, chicken broth, and brown sugar in a bowl. Stir in garlic, red chile pepper, onion, and black pepper.

Put browned tenderloins into slow cooker, cover with the teriyaki sauce mixture. Cook on Low for about 4 hours, turning 2 to 3 times during the cooking time to ensure even doneness. Internal temperature in the tenderloin should reach 180 degrees F (82 degrees C).

Remove tenderloins from the slow cooker and let rest for 5 minutes before slicing. If desired, spoon liquid over slices when serving.