I’ve had a play around with my favourite Lemon Curd recipe, adding whipped egg whites plus mascarpone (or cream cheese), double cream, soured cream, and gelatine. This makes an indulgently rich – but light as mousse – citrussy cheesecake. The pastry is gluten-free but you could use regular flour.
If you prefer to serve the mousse on its own without a pastry crust, see the last footnote.
Serves: 12 – 16
For the pastry:
- 200g gluten-free plain flour, plus additional for rolling
- 1/2 tsp ground ginger
- 1 unwaxed lime: finely grated zest only (save juice/pulp for filling)
- 75g icing sugar
- 25g ground almonds
- 90g cold unsalted butter, cubed
- 1 large egg, beaten (60-70g when weighed in its shell)
- Vegetable oil or cold butter to grease tin
For the filling and garnish:
- 1 unwaxed lemon: grated with a citrus grater to get larger strands, and juice/pulp
- 2 more unwaxed lemons: finely grated zest and juice/pulp
- 1 unwaxed lime: juice/pulp only (see Pastry Ingredients)
- 300ml double cream (300g if weighing)
- 250g mascarpone, or any full-fat soft (i.e., cream) cheese
- 100ml soured cream (95g if weighing)
- 2 large eggs, separated into 2 large bowls (they should be 62-69g each when weighed in the shell)
- 130g white or golden caster sugar, plus 2 extra pinches
- 3 gelatine leaves, with cold water to cover
- Sweet fresh berries (or defrosted from frozen, patted dry) * to garnish (optional)
* Blackberries, strawberries, blueberries, raspberries, currants, etc
- Desiccated coconut nibs, to garnish (optional)
- Icing sugar, to garnish (optional)
- 3 medium to large mixing bowls, plus 3 small bowls
- A round, deep, loose-based pie/tart/flan tin; 24-25cm in diameter and at least 5cm deep
- Baking/parchment paper
- Rolling pin
- Baking beans or beads for blind-baking
- Pastry brush
- A fine zester, plus a citrus grater for larger strands
- A citrus juicer
- An oven-safe plate
- A heavy-bottomed saucepan that fits a large mixing bowl over
- Manual whisk
- Cooling rack
Making the pastry (see Pastry footnote):
- Mix the flour, ginger, lime zest, sugar, and almonds in a medium/large bowl. Add the butter and rub in with your fingers until you have a consistency like fine breadcrumbs.
- Add 1/4 of the beaten egg, and mix manually just until fully combined. Pull it together into a ball – if it seems too terribly crumbly, add a drop or two more of the egg just until the ball holds together. Flatten it into a thick disc and wrap in clingfilm. Chill in the fridge for at least an hour, or overnight.
- Preheat oven to 190 C (170 C fan-assisted). Grease your tin and line with paper.
- Lightly flour a work surface and a rolling pin. Roll out the chilled dough approximately the thickness of a pound coin, to fit the tin so the pastry goes all the way up the sides. If you’re using a fluted tin, ensure the pastry is pushed into each nook and cranny through the paper. Lightly prick it all over with a fork.
- Line the pastry case with baking paper, and pour in baking beads/beans. Blind-bake for around 10 minutes, then remove from the oven. Tip out the beads/beans into a small bowl and discard the lining paper. Return the tin to the oven, and bake for around 15 more minutes until the pastry’s evenly browned.
- Remove the tin from the oven, and brush the pastry all over with the rest of the beaten egg to seal it for the filling. Leave on a cooling rack.
Making the filling and garnish:
- When the pastry’s baked, turn the oven off and spread the largely grated lemon zest on an oven-safe plate, breaking up any clumps, and leave to dry out – door ajar – as the oven cools.
- Heat the finely grated lemon zest and juice/pulp, lime juice/pulp, double cream, mascarpone, soured cream, egg yolks, and 130g sugar in a large bowl over a pot of simmering water (ensure the bottom of the bowl doesn’t touch the water). Whisk manually, quite briskly and frequently, for around 20 minutes until hot (use the ‘pinky test’) and thickened slightly. Turn off the hob and leave the bowl/pot there.
- Cover the gelatine leaves with cold water in a small bowl. Leave for 5 minutes or until softened, then squeeze out all extra liquid and add to the cream mixture, whisking briskly until dissolved. Remove the bowl to a cooling rack and allow to cool for 10 minutes, very gently whisking regularly.
- Beat the egg whites to stiff peaks, starting at low speed and gradually increasing to high speed as the colour and texture change.
- Gently whisk the egg whites into the cream mixture until no large lumps or streaks remain. Pour into the baked pastry shell and drop from an inch height – gently! – to remove any air bubbles. Chill in the fridge for at least 3 hours, preferably longer.
- Scatter berries and/or coconut over the top (if using). Mix 2 pinches of sugar with the dried lemon zest, ensuring all strands are coated, and sprinkle over. You can also dust with icing sugar if you like before serving.
You don’t want the dough to be too damp, even though wetter pastry is easier to handle – it can be really tough in the baked tart, and it can also shrink out of shape when baked. Err on the side of just a teeny bit too crumbly – you’ll work it together when you roll it out, and you can always patch up in the tin.
It takes MUCH less egg than you think it will – so start with only 1/4 of a large beaten egg.
Alternate Preparation Method
If you’re pressed for time on baking day, start the night before:
1- Make the pastry and leave it in the fridge overnight. Put the remaining beaten egg into a sealed container in the fridge, too.
2- Largely zest the 1st lemon with the citrus zester and leave on a plate overnight. With this method, there’s no need to put it in the oven to dry out.
Then the next day, roll out/bake the pastry, cook the filling, fill, and chill.
A) As with my Coffee Mousse recipe, you could dispense with any pastry crust and just serve the lemon mousse in clear glasses, ramekins, etc. You’ll get 6-8 servings in large wine glasses – many more in smaller bowls. TIP: For a more silky-smooth mousse, use only 2 gelatine leaves. Using 3 is fine; it makes a thicker/fluffier/more set mousse, though.
B) Berries are especially good as a garnish for individual servings. Put 1 fruit or a layer of several fruit in the bottom of each glass prior to spooning/funnelling the filling over. After chilling, use more berries to garnish the tops with the lemon & lime zest strands.
C) Don’t forget to drop the glasses/ramekins/etc from an inch height a couple of times to remove air bubbles before putting in fridge, just as with the larger tart. Smaller servings should be chilled enough to serve after 90 minutes or so.
D) I’d also use the citrus grater to create larger lime zest strands (the lime zest you don’t need for the pastry), and add that to the similarly-grated lemon zest on a plate on the countertop, to dry out whilst making and chilling the filling.