1.In a small bowl, combine olive oil, garlic and mustard. Rub over pork. Season to taste.
2.Preheat a char-grill pan on high. Cook pork 8-10 minutes, turning, until well browned and cooked to taste. Transfer to a plate. Rest, covered, for 10 minutes.
3.In a large salad bowl, combine spinach, mandarin, red onion and mint. Thinly slice pork and toss through.
4.To make dressing, in a small jug, whisk all ingredients together. Season to taste. Drizzle over salad and sprinkle with pine nuts.