Prepare the couscous according to packet instructions. Season the salmon with salt and pepper, dip in egg and roll into the couscous. Coat salmon evenly and press tight so that couscous sticks well. Place on a baking tray and cook for approximately 12 minutes in a hot oven. Meanwhile, fry the Jerusalem artichokes in a generous amount of olive oil with the garlic clove, season with salt and pepper. Remove from heat and sprinkle and toss with the Parmesan. In a separate bowl toss together the sliced cherry tomatoes, onion, coriander leaves, orange segments and rocket leaves. Dress with olive oil and the remaining orange juice, season with freshly grated pepper. Serve the salmon accompanied with the Parmesan Jerusalem artichokes and orange salad.