TV chef Nick Nairn makes it look as easy as ABC in his new book. Only he calls it PTH.

"Great food is based on three elements: produce, technique and harmony, or as we refer to them, PTH," he says.

"Whether you're making a five-course meal or a cheese sandwich, these are the areas you need to focus on."

Restaurateur Nairn, who is self-taught, gives a masterclass in everything from choosing which meat, fish, and veg to put in your shopping basket, to the best knives and pans needed to get the job done.

"Buying whole fish and filleting them yourself is the best way to ensure quality and freshness, so don't be afraid to give it a go," encouraged the Scot, who runs the acclaimed Nick Nairn Cookery School on the shores of Menteith Lake, about half an hour from Stirling.

• Nick Nairn Cook School is published by Cassell Illustrated, priced £20.

Potato and watercress soup
30g unsalted butter
1 medium onion peeled and finely diced
2 garlic cloves, peeled and finely chopped
2 medium floury potatoes (about 200g peeled and cut into 5cm dice)
1 litre chicken stock (a stock cube will do)
275g watercress
Maldon salt and freshly ground black pepper
Creme fraiche and chopped fresh chives, to serve
Heat a medium saucepan over a medium heat and add the butter. When melted and foaming, add the onion and sweat for 4-5 minutes over a low heat so that it cooks but doesn't colour. Add the garlic and sweat for a further 2-3 minutes.
Add the diced potatoes and chicken stock and bring to the boil. Reduce the heat to a simmer and cook for 10-15 minutes. Season with a little salt and pepper.
Wash the watercress really well in cold water and pick over to remove any discoloured leaves. Stalks are fine but do remove any extra-thick ones.
Add all the watercress in one go and boil for two minutes. Pour the soup into a blender and liquidize until smooth, passing it through a sieve for a smooth texture or through a chinois (a fine mesh conical strainer) for a super-silky texture.
Serve immediately with a dollop of creme fraiche, chopped chives and extra freshly ground black pepper.


Steak with cabernet sauvignon vinegar and rocket(Serves two)
2 x 225g/8oz rib-eye steaks
2tbsp sunflower oil
20g butter
2 garlic cloves, peeled and crushed
1tsp chopped fresh thyme
4tbsp good quality Cabernet Sauvignon vinegar
2tbsp beef stock
2tbsp olive oil
2 handfuls of rocket
Parmesan cheese, freshly shaved
Maldon salt and freshly ground black pepper
Place a large, heavy frying pan on a high heat. Season the steaks well with salt and freshly ground black pepper. Add the sunflower oil to the hot pan. When it starts to smoke, lay the steaks in the pan and don't move them. It's important to leave the steaks to create a good-coloured crust on the outside.
After 2-3 minutes, little spots of blood will start to appear on the top of the steaks; they're now ready to turn. Turn and cook again for another 2-3 minutes.
Turn the heat down, add the butter, crushed garlic and thyme and baste the steaks. If your steaks have a particularly fatty edge, hold each steak on its side with kitchen tongs, press the fatty edge into the pan, and allow to colour.
Remove the steaks from the pan and place on a warm metal tray in a warm place to rest for at least five minutes.
Take the pan off the heat and allow to cool slightly. Add the vinegar and place the pan over a medium heat, deglaze the pan and reduce the vinegar by half. Add the stock (water or chicken stock will work just as well here) and again, reduce by half. Add the olive oil, give a stir and remove from the heat. The vinaigrette will separate, but that's fine.
Meanwhile place the rocket into a bowl and toss with some of the warm vinaigrette. Place each steak on a warmed plate, pour the rest of the vinaigrette over them and top with the salad and some freshly shaved Parmesan. Serve with cream Dauphinoise potatoes or chips.

Cook school's ultimate bread and butter pudding
100g unsalted butter, softened
500g Italian panettone, cut into 3cm thick slices
500ml full cream milk
500ml double cream
1 vanilla pod
Finely grated zest of 1/2 medium orange
4 free-range eggs
4 free-range egg yolks
180g caster sugar
small pinch of salt
Icing sugar, for dusting
Pouring cream, to serve
Preheat the oven to 160C/325F/Gas mark 3. Generously butter an ovenproof serving dish about 4-5cm depth and a 1.5 litre capacity.
Lightly butter the slices of panettone and lay them in the serving dish, slightly overlapping in a single layer. Do not be tempted to add a second layer as the slices will expand in cooking and too much dough will make the pudding heavy.
To start the custard base, put the milk and cream in a saucepan and bring to the boil. Split the vanilla pod in half, scrape out the seeds and add to the milk pan with the orange zest. Whisk the eggs and egg yolks with the sugar and a pinch of salt until pale. Pour on the hot milk and cream, mixing well.
Strain the cream mix over and around the panettone and let stand for three-four hours.
Place the dish in a roasting tin and carefully pour in hot water so that it half-fills the tin and comes part way up the outside of the dish. Dust the top of the pudding with icing sugar and bake for about 45 minutes. The exact time will depend upon the type of oven used and the warmth of the custard when the pudding goes into the oven. When cooked, it will have a slight crust on top, but will still be slightly wobbly inside.
Remove from the oven and let stand for five minutes .
Spoon portions on to plate, dust with a little more icing sugar and serve with pouring cream.