make the marinade
First, make the pork marinade. Using a blender or an immersion blender, mix together the pineapple, onion, and garlic. Mix until the mixture is completely smooth, then add the oregano, paprika powder, chili sauce, tomato sauce, vinegar, and brown sugar. Season with salt and pepper.
marinate the pork
Arrange a rack at the top of the oven, then preheat it to 240 °C / 460 °F. Transfer half of the prepared marinade to a plate and place the pork tenderloin on top. Roll the meat in the marinade until to thoroughly coat it. Set aside for 10 - 15 minutes or overnight.
make the pineapple salsa
Place the peppers, tomato, and onion on a baking sheet. Don't line the baking sheet with parchment paper. Place in the preheated oven and roast for 15 - 18 minutes at 240 °C / 460 °F. Remove from the oven. Peel the peppers, remove the seeds, and finely chop. Finely chop the roasted tomato, roasted onion, and red onion. Add all the vegetables to a bowl, then add the finely chopped coriander, olive oil, finely chopped fresh pineapple, and lime juice. Season with salt and pepper. For some extra spiciness, feel free to add some chopped chili. Set aside until needed.
roast the pork tenderloin
Place a large pan over high heat. Add the canola oil. Pat dry the pork tenderloin and place it in the hot pan. Sea the meat for about 1 - 2 minutes per side. Place the pork tenderloin on a baking sheet lined with parchment paper. Brush with the rest of the prepared marinade. Place in the preheated oven on the middle rack. Roast for 12 - 16 minutes at 210 °C / 410 °F.TipThe meat is roasted when the thermometer inserted into the thickest part of the meat registers 62 °C / 144 °F.
Heat the tortillas in the pan. Cut the roasted pork tenderloin into thin slices and serve with fresh pineapple salsa wrapped in a warm tortilla.