Preheat the oven to 200ºC/gas 6. For the salad, wrap each beetroot individually in foil and roast for 40 to 45 minutes, or until tender. Leave to cool while you tend to your mackerel. In a large bowl, combine the pomegranate molasses, honey and 40ml of satsuma or orange juice, then season. Place the mackerel into the mixture and leave to marinate for 20 minutes. Carry on with your salad. Peel the onion, pick off and reserve the fennel fronds, then very finely slice with a mandolin if you have one (use the guard!). Peel and slice the satsumas into rounds, then combine with the red onion, fennel and beetroot. Set aside. For the vinaigrette, combine the oil, lemon juice, molasses and honey in a small bowl and whisk well. Set aside until ready to serve. Remove the mackerel fillets from the marinade and place on a baking tray lined with foil. Pour the marinade into a small saucepan and bring to the boil over a high heat. Cook for 5 minutes, or until it’s reduced and thickened enough to coat the back of a spoon. Set aside for the glaze. Preheat your grill to full whack and grill the fillets for 4 minutes, or until the skin turns golden and charred and the flesh firms up. Remove from the oven and brush with the glaze, then season. Drizzle the vinaigrette over the salad and toss to combine. Roughly chop and add the dill and serve alongside the mackerel.