Make salad dressing by combining the first 6 ingredients in a salad bowl. Cover and keep refrigerated until needed.
Preheat your barbecue or indoor grill to medium-high. Place the pork in a shallow-sided dish with the oil, cumin, oregano, paprika, salt and pepper. Turn the pork to coat with the flavourings. Grill the pork, turning occasionally, 15 minutes, or until just cooked through. Rest the pork 5 minutes, and then slice into 16 to 20 pieces.
Toss salad greens with the dressing. Divide and mound the greens on 4 plates. Artfully arrange the pork, nectarines, cheese and pecans on around the salad greens. Serve immediately.