Fill your kettle and boil it. 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 any grit. Finely slice it.

Warm a large pan or casserole dish on a medium-low heat for 2 mins. Add 2 tbsp olive 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 and burn, lower the heat and add a few tbsp 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 and stir. Cook for 10 mins, stirring every so often, till the veg are soft. Fill and boil your kettle again.

Meanwhile, peel the potatoes. Chop them into bite-size pieces. Drain and rinse the butter beans. When the veg are soft, add the potatoes and butter beans to the pan. Tip in the pearl barley and crumble in the stock cube. Add the bouquet garni (if you have any heatproof string, tie the herbs together to make them easier to fish out later).

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

Roughly chop the parsley stalks and leaves. Fish the bouquet garni out of the pan. Halve the lemon and squeeze in a little juice. Stir in most of the parsley (keep a pinch or 2 back for garnishing). Taste and add more lemon juice, salt or pepper if you think it needs it. Ladle into warm bowls, and serve garnished with the remaining parsley.