Peel and finely grate the ginger. Caramelise the sugar in a pan until light. Add ginger and stir until caramel and ginger are mixed. Let the caramel cool down on a piece of baking paper.
Break the caramel into small pieces.
Wash the salmon fillet, dab dry and cut into cubes of about 2 cm thickness. Mix soy sauce and honey in a deep plate. First turn the salmon cubes in the soya-honey mixture, then in the caramel pieces.
Put the cubes on skewers and serve immediately.