For the filling

• 150g (5½oz) pearl barley
• 3 tbsp extra-virgin olive oil
• 1 onion, finely chopped
• 1 celery stick, finely chopped
• 2 garlic cloves, sliced
• 2 tsp thyme leaves
• 1 bay leaf
• 400g (14oz) large floury potatoes, peeled and thickly sliced
• 1 glass of white wine
• 1 litre (35fl oz) vegetable stock
• 1 large knob of unsalted butter
• 500g (1lb 2oz) chestnut mushrooms, thickly sliced
• Sea salt and freshly ground black pepper

For the cobbler

• 175g (6oz) self-raising flour
• 1 tsp fine sea salt
• 75g (2½oz) unsalted butter, cubed and chilled
• 75g (2½oz) mature cheddar, grated
• 1 small handful of chives, finely chopped
• 1 small handful of flat-leaf parsley, leaves picked and chopped
• 1 large egg
• 1 tbsp Dijon mustard
• 150ml (5fl oz) whole milk

First, rinse the pearl barley. Place in a bowl, cover with cold water and soak for 1 hour.

Heat the oven to 200°C/180°C fan/400°F/gas mark 6.

For the filling, heat 1 tablespoon of the olive oil in a large, wide casserole or heavy ovenproof pan. Add the onion, celery, garlic, thyme and bay
leaf. Cover and cook gently over a low heat for 10–12 minutes, stirring occasionally, until the onions are soft and sweet. Drain the barley and
add it to the pan along with the potatoes. Give everything a good stir, then pour over the wine and stock. Replace the lid and bring the filling back to the simmer. Allow to simmer gently while you fry the mushrooms.

Set a large frying pan over a high heat. Add 1 tablespoon of the olive oil and half the butter. When the butter is melted, add half the mushrooms and season with salt and pepper. Fry the mushrooms, turning them regularly, for about 5 minutes, until they are nice and dark and caramelised around the edges. Add the fried mushrooms to the potatoes and barley and bring the mixture back to the simmer while you fry the remaining mushrooms.

Repeat the frying process with the remaining olive oil, butter and mushrooms. Add these to the casserole or pan, as before, and continue to cook the filling, stirring regularly, for about 35–40 minutes, or until the potatoes are just beginning to break down and the barley is tender.

While the filling is cooking, make the cheesy, herby cobbler. Sift the flour and salt into a bowl. Add the butter and rub it in with your fingers until
it feels like coarse breadcrumbs. Add the grated cheese and the herbs along with a generous twist of black pepper. Beat the egg, mustard and milk together in a separate bowl and add to the flour mixture. Stir lightly to bring everything together into a soft, slightly sticky dough.

Taste the filling and add more salt and pepper if it needs it, which it probably will. Remove from the heat and drop large spoonfuls of the herby dough onto the filling – you should get about 6–8 cobbles.

Bake the cobbler for 30–35 minutes, until the topping is well risen and golden and the filling is bubbling away underneath. This is wonderful served with runner beans and leeks.