First pat dry the salmon fillets with kitchen paper. Mix the ginger, cinnamon and cardamom with salt and pepper and sprinkle it over the salmon. Rub in to make sure it is well coated.
Put the orange juice and zest, honey, soy sauce, ginger and garlic into a small saucepan. Heat gently until the honey has melted, then turn up the heat and cook until the volume of liquid has reduced by half. Set aside.
Heat the olive oil in a large frying pan. When it is very hot, add the salmon fillets, skin-side down. Cook for 3-4 minutes until the skin is crisp and the fillets can easily be lifted away from the pan – if they are at all resistant, leave for a little longer.
Turn the fillets over and cook for a further minute, then pour the sauce round the fillets. Cook for a minute or two longer until the sauce is syrupy.
Serve the salmon skin-side up with a little sesame oil drizzled over, the sauce spooned over and couscous on the side.