First make the sauce. Place all ingredients in a small saucepan and cook over a allow heat, stirring until everything is combined. Tip into a small bowl, leave to cool then chill until ready to serve.
Cut the tempeh into thick sliced. Stir together the soy sauce, rice malt syrup and grated ginger in a bowl. Place the tempeh in the marinade, turn to coat a couple of times and leave to marinade for about 10 minutes.
Peel the papaya, remove the seeds and cut into sliced the same size as the tempeh. Thread the papaya and marinated tempeh onto skewers (soaked first if bamboo or wooden), either alternately on the same skewer or on separate ones.
Heat a non-stick frying pan and fry the skewers on each side for a few minutes, or cook on a hot barbecue for 3-5 minutes, turning as needed, until nicely marked on all sides without being burned.
Brush skewers with the remaining marinade while they are being grilled. Serve with the chilled sauce, a few lettuce leaves, fresh mint, coriander and some lime wedges to squeeze over.