Caramelised Onion Gravy

1. Trim, peel and finely slice the onions. Heat 2 tbsp oil in a large frying pan over low heat. Add the onions with a large pinch of salt and pepper. Fry gently, stirring occasionally, for 25-30 mins till the onions are soft and jammy. Cooking them slowly ensures they stay sweet. If they start to dry out and colour too quickly, turn the heat down and add a splash of water.

2. Meanwhile, fill and boil your kettle. Crumble the vegetable stock cube into a heatproof jug and pour in 500ml hot water. Whisk to combine.

3. When the onions are very soft, increase the heat under the pan to medium. Pour in the balsamic vinegar and cook for 2 mins, stirring, till the onions are sticky and amber coloured.

4. Pour 150ml of the vegetable stock over the onions and stir it to deglaze the pan, scraping up any crusty bits from the base of the pan.

5. In a small bowl, combine the cornflour with 2 tbsp cold water. Whisk with a fork to form a smooth paste. Add this to the onions and stir well to combine.

6. Add the bay leaf to the onions. Slowly pour in the remaining stock, a little at a time. Gently simmer for 10 mins to let the flavours develop. Trickle in a little water if you prefer a looser gravy. Taste and adjust the seasoning. Transfer to a gravy boat and serve.

7. Get ahead
This gravy can be made ahead. Store it in an airtight container in the fridge and reheat in in a pan or microwave just before serving.