Sweet and sour roasted red onions

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Sweet and sour roasted red onions

Caramelised on the outside and super-soft within, these are delicious alongside almost any meat or fish. Serves three to four as a side dish.

500g small red onions

2 tbsp olive oil

1 stick celery, finely chopped

1 clove garlic, finely chopped

1 tsp rosemary, picked and finely chopped

1 tbsp concentrated tomato purée

3 tbsp cider vinegar

3 tbsp light muscovado sugar

Salt and black pepper

Preheat the oven to 190C/375F/gas mark 5. Peel the onions and cut them in half from root to tip. Put into a small oven dish, so they fit snugly in one layer.

Heat the olive oil in a small saucepan over a medium heat and add the celery and garlic. Fry gently for about 10 minutes, until soft. Remove from the heat, add the rosemary, tomato purée, vinegar and sugar, and stir so the sugar dissolves. Season generously, then pour over the onions and mix well. Roast for an hour, until soft and caramelised, stirring halfway through. Serve hot, warm or cold.