Boil the kettle. Crumble the stock cube into a large pan filled with 1.5 litres of water and bring to a gentle simmer over a low heat.Melt the butter in a large non-stick casserole pan over a medium heat, then peel, finely chop and add the onion.Trim the tough end off the broccoli stalk, then break the florets into small pieces and set aside. Finely chop the remaining stalk, stir into the casserole pan and cook with a lid on for 3 minutes.Add the pearl barley, stirring to coat, and increase the heat to medium-high. Pour in the cider and let it simmer and bubble away.Add a ladleful of the hot stock and wait until it’s been fully absorbed before adding another, stirring and covering in between additions – it should take about 30 minutes. When there’s 5 minutes to go, stir in the reserved broccoli florets.Meanwhile, to make the pangrattato, place a non-stick frying pan on a medium heat with ½ a tablespoon of oil. Peel, finely slice and stir in the garlic, strip in the thyme leaves and add the breadcrumbs to fry for 5 minutes, or until starting to crisp up, stirring occasionally. Roughly chop and add the walnuts, stirring until toasted, then remove from the heat.Taste and season the pearl barley if needed – if it’s soft, turn the heat right down to low and crumble over the Stilton and Cheddar, then pop the lid on. If it’s not quite there, just stir in a little more stock and give it some time.Divide between warm bowls and sprinkle over the pangrattato and finish with a drizzle of extra virgin olive oil, if you like.