Peel and finely chop the onions. Trim the roots and the top 3cm off the leek. Slice a cross in the top of the leek, then open it out and rinse out the grit. Finely slice it.

Warm a large pan or casserole dish over a medium-low heat for 2 mins. Add 2 tbsp oil, the chopped veg and a pinch of salt and pepper. Cook for 10 mins, stirring occasionally, till the veg have started to soften. If they start to catch, lower the heat and add a splash of water.

While the veg fry, peel and finely chop the carrots and parsnips. Peel and crush the garlic. Add the veg and garlic to the pan. Give everything a good stir, then cook for another 10 mins. Stir every so often, till the veg are soft.

Halve and peel the swede. Chop it into chunks around 2cm across. Drain the butter beans and give them a rinse. When the veg are soft, add the swede and butter beans to the pan. Tip in the pearl barley. Crumble in the stock cubes. Add the bouquet garni (if you have any heatproof string, tie the herbs together to make it easier to fish them out at the end).

Pour in 1 ltr boiling water. Cover, bring to the boil, then turn the heat down. Simmer the stew for 30 mins till the veg and pearly barley are tender.

Roughly chop the parsley leaves. Lift the bouquet garni from the pan. Halve the lemon and squeeze in the juice. Taste and add a pinch more salt and pepper if you think it needs it. Ladle into warm bowls to serve, garnished with the parsley leaves.