Preheat your oven to 240°C/220°C fan/gas mark 9.

Peel the sweet potatoes and chop into 2cm chunks. Halve and peel the onion, then cut each half into 3 wedges.

Put the sweet potato chunks and onion wedges onto a large baking tray. Drizzle with oil, season with salt and pepper, then toss to coat. Spread out in a single layer. TIP: Use two baking trays if necessary. 

When the oven is hot, roast on the top shelf until golden, 18-20 mins. Turn halfway through.

Meanwhile, remove the puff pastry from your fridge and allow to come up to room temperature.

Drain and rinse the lentils in a sieve.

Peel and grate the garlic (or use a garlic press).

Heat a drizzle of oil in a large frying pan on medium-high heat.

Once the oil is hot, add the garlic, korma curry paste and curry powder mix. Stir-fry for 1 min. Season with salt and pepper.

Stir in the creme fraiche, vegetable stock paste, lentils and water for the sauce (see pantry for amount). Bring to a boil, then reduce the heat slightly. Simmer until thickened, 5-7 mins.

Add the spinach to the pan a handful at a time until wilted and piping hot, 1-2 mins.

When the veg have roasted, stir them into the sauce. 

Stir through the mango chutney. Taste and season with salt and pepper if needed. Add a splash of water if it's a little too thick.

Once the pie filling is cooked, transfer it to an appropriately sized ovenproof dish. 

Cover with the pastry (see ingredients for amount), pressing it over the sides of the dish or just sitting it on top, then trimming off any excess.

Using the excess pastry, cut out as many decorative shapes as you want.

Pop your pastry creations on the pie and make a small hole in the middle to allow steam to escape. TIP: Brush the pastry with a little milk if you have some.

Bake your pie on the top shelf of your oven until golden brown, 15-20 mins. 

Once your pie is out of the oven, allow it to stand for 2 mins.

When ready, share your curried pie between your plates.