1.In a small bowl, combine pork, sherry, soy and sugar. Mix well; chill, covered, 20 minutes.
2.Meanwhile, heat oil in a wok or large frying pan on high. Stir-fry pumpkin, in 2 batches, 5-6 minutes each batch, until golden and almost tender. Set aside.
3.Drain pork, reserving marinade. Stir-fry pork, in 2 batches, 3-4 minutes each batch. Set aside.
4.Add onion, capsicum, garlic and cardamom to wok; stir-fry 2-3 minutes.
5.Return pumpkin and pork to wok with reserved marinade; stir-fry 1-2 minutes, until mixture comes to the boil. Reduce heat to medium.
6.Toss spinach through and serve with lime wedges, if liked.