Cooking a Seasonal Vegetable Pie with Root Crops

Why Root Crops Belong in a Winter Pie

There is something deeply satisfying about pulling carrots, parsnips and leeks from cold ground and turning them into supper the same afternoon. Root crops store well, roast beautifully and, crucially, they hold their shape when baked under a pastry lid. Unlike softer vegetables, which collapse into a mush, a good carrot or parsnip keeps a little bite, giving the pie texture as well as sweetness.

A seasonal vegetable pie is also forgiving. If you have three parsnips instead of two, or a handful of swede lurking in the veg rack, use it. The method stays the same. What matters is that the vegetables are cut to a similar size, cooked through before they go in the dish, and coated in a well-seasoned sauce that will not turn watery in the oven.

What You Will Need

This quantity fills a 1.5-litre pie dish and serves four generously, or six with a good pile of mash alongside. A deep enamel pie dish or a sturdy ceramic one works best; a shallow tin will leave you wrestling with pastry that overhangs and burns.

• 2 medium carrots, peeled and cut into 1cm rounds
• 2 parsnips, peeled, woody cores removed, cut into 1cm chunks
• 3 medium floury potatoes, such as Maris Piper, peeled and cubed
• 2 leeks, trimmed, washed thoroughly and sliced into 1cm rings
• 40g butter, plus a little extra for greasing
• 40g plain flour
• 400ml vegetable stock, hot
• 150ml whole milk or single cream
• 1 tsp wholegrain mustard
• A few sprigs of thyme, leaves picked
• 1 bay leaf
• Freshly grated nutmeg, salt and black pepper
• 320g puff pastry, or 250g plain flour and 125g cold butter if you are making rough puff
• 1 egg, beaten, for glazing

Preparing the Vegetables

Start by bringing a large pan of salted water to the boil. Add the carrots and parsnips first and cook for four minutes, then add the potatoes and cook for a further four. You want them firm but no longer raw in the middle — a knife should slide in with slight resistance. Drain well and leave them in the colander to steam dry for a few minutes. Wet vegetables make a wet pie.

While they drain, melt the butter in the same pan over a low heat and add the leeks with a pinch of salt. Sweat them gently for eight to ten minutes until soft and glossy, not coloured. Add the thyme leaves and stir for another minute until fragrant. This slow sweat is where the sweetness comes from, so do not rush it over a high flame.

Building the Filling

Sprinkle the flour over the leeks and stir constantly for a full minute. This cooks out the raw floury taste and stops the sauce turning gluey later. Pour in the hot stock a little at a time, whisking as you go to keep it smooth, then add the milk, mustard, bay leaf and a good grating of nutmeg. Simmer gently for five minutes until the sauce coats the back of a spoon.

Return the drained root vegetables to the pan, fold them through the sauce and season generously. Root vegetables need more salt than you might expect, so taste and adjust. Fish out the bay leaf, then tip everything into your buttered pie dish and level the top. Leave it to cool for at least twenty minutes. Hot filling will melt the pastry from underneath and leave you with a soggy base.

Rolling Out the Pastry Lid

Roll your pastry on a lightly floured surface to about 3mm thick, a little wider than the dish. Brush the rim of the dish with beaten egg, then lay the pastry over the top and press it firmly against the rim all the way round. Trim the excess with a sharp knife, leaving a 2cm overhang, and crimp or fold that overhang under itself to seal.

Cut two or three small slashes in the centre of the lid so steam can escape. Without them, the filling will bubble up around the edges and the pastry will lift. Brush the whole lid with beaten egg and, if you like, decorate with a few pastry leaves made from the trimmings. Chill the assembled pie in the fridge for fifteen minutes before it goes in the oven — this helps the pastry puff properly and keeps the edges crisp.

Baking, Serving and Storing

Heat the oven to 200°C (180°C fan, gas mark 6). Bake the pie on a baking tray on the middle shelf for 35 to 40 minutes, until the pastry is deep golden and the filling bubbles at the slashes. If the edges start to catch, cover them loosely with foil for the last ten minutes.

Let it stand for five minutes before serving. This pie wants gravy — a thin, dark onion gravy poured at the table, not over the pastry. Serve with buttered greens, or simply a dish of pickled red cabbage to cut through the richness. Any leftovers keep in the fridge for two days and reheat well, though the pastry will soften. To avoid that, lift the lid off, warm the filling through in a pan and crisp the pastry separately in a hot oven for a few minutes.

Come February, when the stored carrots are starting to soften and the parsnips have gone sweet from the frost, this is the pie to make. It turns the tail end of the winter veg into something worth sitting down to.