Peel the garlic cloves, roughly chop them and mash them to a paste with the side of a knife. Sprinkling a little of the salt over them helps with this process.
Add all of the ingredients for the tandoori marinade to a bowl and give everything a good mix.
Remove the skin from the salmon and cut the flesh into 2cm-2½cm (¾"-1") cubes then add it to the marinade, mix to coat and allow to sit for at least 2 hours. (You go as long as 4 hours)
Thread the salmon onto skewers (soaked if they are bamboo).
Preheat your grill/broiler as high as it will go before you do this.
Cook the skewers under the grill for 2½-3 minutes per side.