Basil & pink grapefruit posset tart

The flavours mingle beautifully in this luxurious soft-set tart.

SERVES 8 PREP 25min PLUS (overnight) chilling

FOR THE CRUST

• 175g gingernut biscuits

• 50g butter, softened

• 1tbsp runny honey

FOR THE FILLING

• 2 pink or ruby grapefruits

• 8g fresh basil leaves (from a small handful of sprigs)

• 3tbsp icing sugar

• Juice 1 lemon

• 250ml double cream

• 100g condensed milk

TO DECORATE, OPTIONAL

• 1 medium egg white*

• Small fresh basil sprigs or leaves

• Caster sugar, to dredge

• Icing sugar, to dust

• Grapefruit segments

Whizz biscuits in a food processor until finely crushed. Add butter and honey; whizz again until incorporated. Empty into a 20.5cm round, straight-sided, loose-bottomed tart tin. Using fingers, work the mixture evenly over base and 2.5cm up sides of tin, compacting it as firmly as possible. Chill for 15min.

Finely grate zest from 1 grapefruit and put into a mini food processor

(or the small bowl of a large one).

Add basil leaves and icing sugar; whizz until basil is very finely chopped. Scrape into a large bowl.

Squeeze juice from 1½-2 grapefruits through a fine sieve – you need 150ml. Add lemon juice. Set aside.

To basil mixture, add cream and condensed milk. Beat with a handheld electric whisk until cream holds medium peaks. Add citrus juice; beat again until fairly stiff. Scrape into the biscuit base and level. Chill to set for at least 6hr, or overnight.

To decorate (optional), crystallise some basil sprigs. Whisk egg white until frothy. Paint scantily on to basil sprigs or leaves, then dredge in caster sugar. Set aside on baking parchment to harden.

Just before serving, arrange grapefruit segments on a baking tray. Dust with a little icing sugar.

Use a blowtorch (see Cook’s tip) to add a little caramelisation. Cool.

Transfer tart to a cake stand or plate. Decorate with crystallised basil and grapefruit, if you like. Serve immediately.

PER SERVING (WITHOUT DECORATION): CALS 385; FAT 27G; SAT FAT 17G; CARBS 31G