THIS week, inspired by looking through some old clippings, we’re having a go at a bit of a trusty old faithful, cottage pie.

But this one is a completely vegetarian version, based on a recipe by the ever-reliable Nigel Slater.

I decided his recipe was a tad on the bland side, so re-worked it with a few extra herbs and vegetables, plus a kick of tomato to enrich and enliven the sauce.

Cottage pie must be one of my very favourite dishes, that super-satisfying combination of rich, saucy beef mince slow-cooked beneath a pillow of creamy smooth mashed potato.

Along with its ovine cousin, the shepherd’s pie (and the rarer cheese-topped Cumberland pie) it’s a copper-bottomed British classic. And, when the weather’s as dreadful as it is right now – again I’m writing this whilst trying to make out the other side of the valley through the wet gloom – a cottage pie does the trick perfectly.

Not too heavy, not too flimsy – a delightful suppertime treat. A dollop or two of creamy mashed potato, and also a handful of fresh emerald-leaved spinach, adds balance to the richness.

The meat in this particular pie is replaced by one of my very favourite ingredients, Puy lentils.

Lentils are amazingly useful kitchen ingredients, and it’s always handy to have a bag in the store cupboard.

Their nutty flavour and chewy texture can transform a humdrum dish into a thoroughly satisfying plateful.

As they require no pre-soaking, they can be ready in a matter of minutes, and a spoonful of these brilliant pulses, perhaps simmered in vegetable stock then lightly-buttered, makes a lamb chop incredibly happy, and sausages positively sizzle with delight.

To my mind, the very best come from the fertile soils around the small town of Le Puy-en-Velay in France, not far from Saint-Etienne.

Here, a serendipitous combination of topography, soil conditions and climate provide the perfect ‘terroir’ for the lentil plants, and the resulting pulses are incredibly full of flavour, and jam-packed with anthocyanins, which, and I’ll spare you the boring science bit, are very good for you indeed.

The culinary use of these lentils is vast, from smooth, rich soups to stews and pies.

Cooked and chilled, they make wonderful barbecue-ready salads – just try adding some diced vegetables like peppers and onions, then dress the whole lot with your favourite vinaigrette.

Warmed through, especially with a knob of butter and a few fresh herbs, they are amazing with fish and seafood (scallops especially), and they also provide a wonderful textural and flavour balance to dishes using roast poultry and game. ‘Pigeon aux lentilles’ is a French classic, especially with the exquisite addition of smoked bacon to the finished lentils.

So you see, there’s very little a lentil can’t do – it works across all temperatures, and with almost any ingredient you’d care to choose – vegetarian or otherwise.

Of course, you don’t have to insist on Puy lentils. Many other lentils are wonderfully flavourful, be it black beluga lentils from Canada, or the humble green lentil, which you can find almost anywhere.

Just make sure they’re not overcooked (they need that slight nutty bite to really show off their talents) and flavoured with good, sympathetic aromatics such as thyme, garlic, rosemary, or any of the curry spices such as ginger, cumin, coriander or chili.

I guarantee you’ll be a lentil-lover in no time. Aprons on!

For the lentil mix:

600g Puy or green lentils

2 medium onions, finely chopped2 carrots, finely chopped

2 sticks celery, finely chopped

½ bulb fennel, finely chopped12 chestnut mushrooms, diced small

2 cloves garlic, minced

1 tsp finely chopped parsley

1 tsp finely chopped rosemary

1 tsp finely chopped thyme

2 tbsps tomato puree

Extra-virgin olive oil

1 glass dry white wine

200ml strong vegetable stock

For the topping:

2 x 250g bags fresh spinach

1kg potatoes (Desirée are perfect)

100g butter, plus a little extra

A little double cream

1 egg yolk

S&P

Method:

Make the mashed potato; peel the potatoes, dice and boil them until tender (about 15-20 min), then pass them through a mouli or mash by hand.

Heat the cream and reduce by half, then add butter and whip this into the potato.

Whip in the egg yolk, season well and reserve. Wash the spinach thoroughly.

Toss the washed spinach with a little ground black pepper in sizzling butter for a few seconds until it is just wilted. Tip onto a plate and reserve until needed.

To make the lentil base, gently heat a good slug of olive oil, and cook the carrots, onion, celery, fennel and garlic for 15 minutes until they begin to colour.

Add the mushrooms and the lentils and sweat for a few minutes, then add the white wine and reduce until completely evaporated. Then, tip in the stock, bring to the boil and simmer for 20 minutes.

Add the herbs and tomato puree. Check for seasoning and adjust if necessary. If there’s too much liquid, either pour it off or strain the liquid off and reduce it to a syrupy consistency in a pan, then stir it back into the lentil mix.

To make up the pie, fill the dish with the lentil mixture, and top with the wilted spinach.

Finally, smooth over the mashed potato, and heat the oven to 200ºC / Gas 6. Bake the pie until it is bubbling and golden-crusted.