Method

​1 Start by making the pastry: in a bowl, rub the gluten-free flour and butter together into breadcrumb size. Stir in the caster sugar. Beat the egg into a separate jug, then gradually add the egg into the flour, butter and sugar mix. With your hand bring together the pastry into a ball. Cling film and put in the fridge for 15 minutes.

2 Roll the pastry out to the thickness of a £1 coin. I roll the pastry out between two sheets of cling film as it is less messy. Transfer the pastry to a loose-base flan tin. Gently push the pastry into place and remove some of the excess pastry - leaving enough pastry to just go over the rim of the tart as this will shrink during cooking. This can be trimmed and tidied up once the tart has been cooked. Chill the pastry for a further 15 minutes in the fridge.

3 Preheat your oven to 180°C/fan 160°C/gas mark 4

4 Line the pastry with greaseproof paper, filling with baking beans or dried pulses (or rice if you have none of these). Bake ‘blind’ for 20 minutes. Remove beans and paper and continue baking for 20 minutes until cooked through. Reduce the oven temperature to 170°C/fan 150°C/gas mark 3.

5 For the custard filling; place the cream and butter in a saucepan and bring it up to a gentle simmer. Whisk the beaten eggs and sugar together in a large heatproof jug using a balloon whisk – but not too vigorously because you don't want to make bubbles.

6 Pour the hot cream and butter liquid over the beaten eggs, add the vanilla extract and half the freshly grated nutmeg and whisk briefly again.

7 Now place the tart on a baking tray with the oven shelf half out and pour the filling into the tart (it will be very full). Scatter the rest of the nutmeg all over, then dot with butter. Bake in the oven for 40 minutes until the filling is golden brown, firm in the centre and slightly puffed up. Serve either warm or cold, your choice!