Photo: Toby Scott
Preheat the oven to 200°C, fan 180°C, gas 6. Wash and trim the beetroot and cut into wedges; transfer to a large roasting tin. Sprinkle over the cumin seeds and 1 tablespoon of the oil; season and toss. Cover with foil; bake for 40-45 minutes until tender.
Meanwhile, peel and slice the shallot finely and transfer to a bowl; add the vinegar and set aside. Zest ½ of one of the oranges and set aside. Then, using a sharp knife, top and tail all 3 oranges and cut away the pith and peel. Cut into segments; collect any juice into a jug. Also squeeze the pithy middles of the oranges into a jug – you need about 3 tablespoons of the juice.
Cook the kale in a large pan of boiling salted water for 3-4 minutes (or steam); drain.
Strain the shallot, adding the vinegar to the orange juice in the jug, season and whisk in 2 tablespoons extra-virgin olive oil. Taste and season; stir in the dill.
Toast the pumpkin seeds in a dry large frying pan over a medium heat for 1-2 minutes, shaking the pan occasionally so that they toast evenly. Transfer to a bowl.
Once tender, remove the beetroot from the oven; mix with the kale and set aside.
Rub the remaining tablespoon of extra- virgin olive oil over the mackerel fillets on both sides and season them. Return the frying pan to the heat; when hot, add the mackerel fillets skin-side down and fry for 3-4 minutes over a high heat, then flip over and cook for a further minute or two until cooked through.
Add the orange segments and shallots to the beetroot and kale, pour over the dressing and toss to combine. Divide between 4 plates. Top each plate with 2 mackerel fillets; sprinkle with pumpkin seeds and a little orange zest.