Like herring, mackerel contains omega-3 fatty acids which, unless you've been living on the moon for the past 20 years, have long been identified as critical to a healthy lifestyle.

In essence, the more mackerel you eat the better your body will perform.

Mackerel spoils so quickly that it is almost always eaten salted, smoked or pickled, the last of which is my favourite. This week's dish is a tasty example but please note that the pickling process takes two days, so if you're looking for instant gratification you'd better look elsewhere.

Marinated mackerel with beetroot

Serves 4

[bold]Marinated mackerel [end bold]

500ml water

200g sugar

100ml white wine vinegar

15 black peppercorns

4 bay leaves

8 mackerel fillets

2 red onions, finely sliced

2 large beetroots, uncooked

1 shallot, chopped

2tbsp white wine vinegar

2 celery sticks, peeled

A pinch of rock salt

2tbsp olive oil

1tsp fresh chopped chives

A small bunch of fresh chervil

For the marinade, bring the water, sugar, vinegar, peppercorns and bay leaves to the boil in a pan then turn off the heat.

Leave the marinade to cool then transfer it to a large bowl and add the red onions and mackerel fillets. Cover with clingfilm and leave to marinate for 48 hours.

When you're ready to assemble the final dish, set the oven to 190C/gas mark 5. Wrap the beetroot in tinfoil and bake in the oven for 1 hour, then leave it to cool before peeling the beetroot and cutting it into wedges.

Mix the beetroot with the shallot and white wine vinegar, adjusting the amount depending on taste.

Peel the celery and cut it into thin slices then cook it in boiling water for 30 seconds. Strain off the water and add the celery to the beetroot. Remove the mackerel from the marinade and drain it on paper towel. Place two fillets on each plate and arrange some beetroot and celery alongside them. Add some of the red onion from the marinade then sprinkle with rock salt and drizzle with the olive oil.

Finish with some chopped chives and chervil leaves.