White Chocolate Creme Citron Tarts

For a family lunch today, I decided to really blow out on dessert. For the platter of sweet miniatures, I made downsized portions of Espresso Orange Panna Cotta Parfaits with Coffee Gelee from Claudia Fleming's The Last Course, Triple Chocolate Mousses from Alice Medrich's Bittersweet, and White Chocolate Creme Citron Tarts from Fran Bigelow's Pure Chocolate. I've learnt from making the layered panna cotta previously that in order for the balance to work, the intense coffee gelee layer should be relatively thin so it doesn't overwhelm the creamily delicate flavours atop (orange panna cotta) and beneath (espresso panna cotta). As for the Triple Chocolate Mousses, Keiko of the breathtakingly beautiful Nordljus has recently posted the recipe, alongside the requisite exquisite picture.

The little tarts, based on a recipe I've been meaning to try, combine white chocolate with lemon curd, two of my favourite foods - even on paper, I figured, how could it taste anything but divine? A classic lemon curd is enriched by the addition of white chocolate, which partially replaces the quantity of butter. I've added the additional step of flavouring the sugar with lemon zest before whisking it with the egg yolks - it's something I like doing when making citrus curd, finding that it heightens the flavour. To eliminate the possibility of lemony scrambled eggs, I cook the mixture in an improvised bain marie instead of over direct heat. After the curd is mixed with the white chocolate (but before the butter goes in), I also push the mixture through a chinois to ensure smoothness. And instead of the sugar tart crust called for, I've adapted the author's chocolate wafer tart crust, a cookie-like dough with a real depth of chocolate flavour. I've essentially halved her recipe; this still makes enough dough for a dozen tarts - you could either double the filling recipe below, or freeze the extra pastry-lined tart pans, carefully wrapped to protect against frostbite, for some future project.

White Chocolate Creme Citron Tarts
(Adapted from Pure Chocolate by Fran Bigelow)

1/2 cup caster sugar
1 Tbsp finely grated lemon zest
4 large egg yolks
1/3 cup freshly squeezed lemon juice
2 ounces white chocolate, very finely chopped
4 Tbsp unsalted butter, cut into 1/2 inch cubes, softened at room temperature
6 Chocolate Wafer 3-inch tart shells, blind-baked and cooled (recipe follows)

Blitz the sugar and lemon zest together in a processor or blender until the sugar is pale yellow and fragrant; the heat helps release the aromatic essential oils into the sugar. Whisk the yolks and sugar together in a medium heat-proof bowl until smooth. Add the lemon juice and whisk again. Place the bowl over a pan of gently simmering water. Cook the mixture, stirring constantly with a spatula and being sure to scrape the bottom and sides of the bowl, until it thickens (the consistency should be like that of sour cream), but do not let the mixture come to the boil. Immediately take the bowl off the pan, add the white chocolate, and stir until completely smooth. Push the mixture through a chinois or other fine-meshed sieve into a mixing bowl, preferably one that's spouted. Now add the butter, which should be very malleable but still cool, a few cubes at a time, stirring each addition until completely incorporated before adding the next. The final texture should resemble that of mayonnaise.

Carefully pour filling into the baked tart shells and chill to set, about 4 hours. The filled tarts can be made up to 2 days in advance, stored in the fridge. Bring back to room temperature by taking them out 1 hour before serving. If you wish, garnish with dark chocolate shavings or lemon zest.

Serves 6

Chocolate Wafer Tart Shells
6 Tbsp unsalted butter, room temperature
1/2 cup caster sugar
1/3 cup Dutch-processed cocoa powder, sifted
1/8 tsp fine sea salt
1 large egg yolk
1 tsp pure vanilla extract
1/2 cups plus 2 Tbsp plain all-purpose flour

Cream the butter and sugar together in a mixer with the paddle attachment on medium-high speed until fluffy, about 4 minutes. Add the cocoa and salt, mixing on low speed till well combined, scraping down the sides of the mixing bowl. Add the egg yolk and vanilla, blending thoroughly, again scraping sides of bowl. Add flour on the lowest speed until the dough just comes together. Do not overwork. Divide dough into two equal portions, pat into fat discs, wrap in clingfilm, and let rest in fridge, at least 4 hours or overnight.

Use 1 disc of dough for 6 tart shells. On a board dusted with a mixture of half cocoa and half flour (this terrific tip from Fran Bigelow helps keep the dark crust, well, dark), and using a similarly dusted rolling pin, begin rolling from the centre out, lifting and turning constantly, until the dough is a uniform 1/8 inch thickness, keeping the board and pin dusted as necessary to prevent sticking. If the dough becomes unmanageable at any point, stick the whole set-up (board and all) into the fridge for about 15 minutes or so before picking up where you left off. Do this as often as is necessary - a cold spell cures most evils. Once rolled out, dust off excess flour with a pastry brush, and stamp out circles using a round cookie cutter before pressing into the lightly buttered 3-inch tart pans, making sure the pastry is an even thickness throughout bottom and sides. Trim excess dough along edges with a sharp knife. Chill lined tart pans for at least 2 hours, or until very firm. Preheat oven to 350 degrees Fahrenheit. Blind-bake using rounds of baking parchment weighted with rice, beans, or pastry weights for 15 minutes. Gingerly remove parchment and weights. Continue baking another 3 to 5 minutes, until tart shell bottoms are set and dry to the touch. As it's hard to tell when this pastry is done given its colour to begin with, it's best to keep a watchful eye.