Place salsa ingredients in a bowl and gentle toss to combine. Cover and allow flavours to meld in the fridge 30 minutes. Preheat barbecue or indoor grill to medium-high heat. Brush pork with oil, then season with cumin, chili powder, salt and pepper. Grill 3-4 minutes per side, or until cooked through. Place pork on plates and top with a generous spoon of the salsa.