Method

1. Peel the celeriac, chop into 2.5cm/1-inch chunks and place in a pan of cold water. Place on the hob, bring to the boil and simmer until tender, about 20 minutes. Mash the celeriac with 100g/3½oz of the butter and season with salt and freshly ground black pepper. Keep covered and warm.

2. Meanwhile, peel, halve and thinly slice the onion lengthways into semicircles. Heat the olive oil in a heavy-bottomed frying pan and cook the onions on a medium high heat until soft and lightly coloured.

3. Cut the apples into quarters and cut out the cores out, then cut them again into eighths.

4. Remove the onions from the pan, add the remaining 50g/1½oz butter and place the apples in. Cook over a medium heat. When they are golden brown turn them over so that they are beautifully coloured on both sides.

5. Return the onions to the pan with the apples, raise the heat and add the ale to the pan. Adjust the seasoning and continue cooking until the apples begin to break down a little and the liquid has reduced by at least half and has thickened somewhat.

6. With a sharp knife score the skin of the chops and season them. This will help the chop to crisp when it is cooked.

7. Heat a griddle pan until smoking hot. Rub the pork chops with some vegetable oil (this will help prevent sticking) and place the chops on the hot griddle. Cook, turning as necessary, until the meat is cooked through (cooking time will depend on the thickness of the chops; it will be cooked when the juices run clear when pierced with a sharp knife near the bone).

8. For the salad, make the vinaigrette. Place the mustard, vinegar and olive oil in a bowl and whisk. Season to taste.

9. When the chops are cooked, remove from the griddle, and put covered on a plate in a warm place for five minutes. Meanwhile, whisk a knob of butter into the sauce to thicken it slightly.

10. To serve, divide the mash among four plates, place a chop on each dollop of mash and pour the mustard and ale sauce over it. Dress the rocket with the vinaigrette and serve on the side.