Finely slice the onion into rings and put them in a sieve.

Put the vinegar, sugar, salt and peppercorns in a saucepan, bring to a simmer and cook for a minute, stirring so the salt and sugar dissolve.

Take off the heat.

Fill and boil the kettle, then pour the boiling water over the onion rings and leave to drain and cool.

Once the onions are cool to the touch, pack the rings into a sterilised 500g jar, then pour over the warm pickling liquor, seal and leave to steep for at least two hours.

Drain the beans, reserving all the jar liquor, and set aside a few whole beans to use as a garnish at the end.

Put the rest of the beans in a blender with the olive oil, lemon juice and zest, and blitz until completely smooth; you may need to add a splash of water to achieve the smoothest consistency.

Add the reserved jar liquor, season to taste and blitz again.

The velouté is now ready, to be served at room temperature or gently warmed through.

Wipe all the mushrooms with a damp cloth, then cut into equal-sized slices.

Put a drizzle of oil in a large frying pan on a high heat, then add all the mushrooms and, after a couple of minutes, when they begin to crisp and take on a bit of colour, add the butter and garlic, and season to taste.

Cook for a further couple of minutes, until the mushrooms are browned, then lift them out of the pan and spread out on a plate lined with kitchen paper, to soak up any excess water.

Discard the garlic.

Now to finish the dish.

Toast the pumpkin seeds in a 180C (160C fan)/350F/gas 4 oven for 12 minutes, then remove and season immediately with salt and espelette pepper.

Divide the cooked mushrooms and reserved whole butter beans between four soup bowls.

Pour the velouté à table for a dash of wow factor, then serve topped with some pickled onions, toasted seeds and parsley.

If you like, finish with a drizzle of extra olive oil or, my favourite, crispy chilli oil.