Halve the salmon fillets lengthways, then cut the skin off each piece. Scatter the sesame seeds across a plate, then lay the salmon slices in them to completely coat one side only. Pour the excess sesame seeds into a pestle and mortar and pound into a paste. Pick and pound in most of the mint leaves, saving the pretty ones, muddle in the juice of 1 orange and a swig each of extra virgin olive oil and red wine vinegar, then season to perfection. Put a 30cm non-stick frying pan on a medium-high heat, add the grains with a good splash of water, and heat through. Once hot, pour in the dressing, toss together well, then remove to a platter or serving bowl.Wipe out the pan, return to a medium-high heat, fry the salmon skin for a couple of minutes, until crispy on both sides, then remove. Add the salmon, sesame side down, and fry for 3 minutes, then flip for 1 minute on the other side, or until cooked through. Meanwhile, wash the carrots and use a speed-peeler to peel them into ribbons. Toss in a drizzle each of extra virgin olive oil and red wine vinegar, season, and add to the grains. Peel the remaining orange, finely slice into rounds, divide between your plates and sit the salmon and crispy skin on top. Spoon over the harissa, then sprinkle both salmon and grains with the reserved mint, to finish.