WHAT YOU NEED

For the sweet pastry

115 g (4 oz) caster (superfine) sugar
60 g (2 oz) butter, chilled and cubed
25 g (1 oz) egg, beaten (about ½ a large egg)
½ teaspoon vanilla bean paste (or extract)
150 g (5¼ oz) *basic flour blend, plus extra for dusting
½ teaspoon xanthan gum
⅛ teaspoon salt
1 tablespoon milk (if needed)
1 egg white
2 tablespoons single (light) cream

For the custard filling

320 ml (11 fl oz) double (heavy) cream
2 teaspoons vanilla bean paste (or extract)
4 egg yolks
45 g (1½ oz) caster (superfine) sugar
⅛ teaspoon salt

For the brûlée

6–8 teaspoons caster (superfine) sugar

*For the basic flour blend

Makes 1 kg (2¼ lb)
315 g (11¼ oz) rice flour
250 g (9 oz) tapioca starch
250 g (9 oz) gluten-free cornflour (cornstarch)
165 g (5¾ oz) potato starch
2 tablespoons + 1 teaspoon xanthan gum

Makes 2 kg (4½ lb)
630 g (22¼ oz) rice flour
500 g (17¾ oz) tapioca starch
500 g (17¾ oz) gluten-free cornflour (cornstarch)
330 g (11½ oz) potato starch
40 g (1½ oz) xanthan gum

To make the basic flour blend

Sift the ingredients into a large bowl and mix until well combined. Sift and mix again to ensure the starches and xanthan gum have been evenly distributed into a homogenous flour blend. Store in an airtight container until ready to use.

To make the tart

Start by making the pastry. Preheat the oven to 160°C Fan (325°F Fan) and grease an 18–20 cm (7–8 in) fluted tart tin.

Cream the sugar and butter in a large bowl with a hand-held electric beater or in a stand mixer fitted with a whisk attachment. Add the egg and vanilla and continue mixing until well combined.

Sift together the dry ingredients, then add them to the egg and butter mixture. If using  a stand mixer, mix a little by hand (to avoid blowing the flour out of the bowl), then switch to a paddle attachment and mix on medium speed until soft and smooth (this will take a few minutes). If mixing by hand, bring the dough together with a sturdy spatula, then knead it by hand until smooth and pliable. If needed, add a little of the milk – just enough for the dough to be soft and workable. Wrap the dough loosely in cling film (plastic wrap) and squash it into a thin disc. Refrigerate for 10–15 minutes.

Lightly dust your work surface with flour and remove the dough from the plastic. Dust the dough as well, then use a rolling pin to roll it out until it’s 2–3 mm (1⁄16–1⁄8 in) thick.

Carefully transfer the pastry to the tart tin, gently pressing it to the base and edges before cutting away the excess pastry. Prick the base of the tart case all over with a fork, then place on a baking sheet and transfer to the oven for 16–18 minutes.