Smoked mackerel is inexpensive, sustainable and very tasty. It works wonderfully with horseradish, which cuts through the oiliness of the fish, and the sweet potato and slightly pickled beetroot add interestingly balanced flavours.

Most supermarkets do an own-brand smoked mackerel, which is generally good quality – otherwise, get it from your local fishmonger.

Serves 2

2 sweet potatoes, washed and cut into large dice

40ml olive oil

2 garlic cloves, crushed

2 medium beetroots, washed and cut into quarters

2 sprigs of thyme

2 smoked mackerel fillets, flaked

20ml red wine vinegar

2 tsp horseradish cream

1 tbsp chopped, flat-leaf parsley

Preheat your oven to 180C. Take a large baking tray, add a dash of olive oil and place in the oven. When the tray is hot, place the sweet potato and crushed garlic on it, season and cook in the oven for 15 minutes, until soft.

Meanwhile, heat a dash of olive oil in a frying pan, then add the beetroot and thyme.

After four minutes, add the red wine vinegar and 100ml water, cover but keep an eye on it because you may need to add more water. Simmer until the beetroot is cooked (about 15 minutes).

When the beetroot is ready, allow to cool, then mix with the sweet potato and flaked mackerel. Season, finish with the flat leaf parsley, and serve with the horseradish.

• Angela Hartnett is chef patron at Murano restaurant and consults at Whitechapel Gallery and Dining Room, London. @AngelaHartnett