Rhubarb & Custard

Custard filled tart topped with a light forced rhubarb & ginger mousse

Full disclosure: I don't like rhubarb. It's one of about 3 ingredients I've never been able to eat.

Sometimes though, I'll venture over to the dark side of the things I hate and try to find a way to love it like everyone else - and, for the first time, it worked; I've been converted to the joys of the manky pink celery stuff.

This recipe was inspired by my favourite chef, Raymond Blanc, and his new show about Kew Gardens. If you've not seen it, I'd recommend it. He made a rhubarb & custard dessert which looked delicious, and made me think "how bad can it really be?"

So here's my take on it - a rhubarb & ginger mousse lightened with Italian meringue, on a pastry base filled with vanilla custard, and Raymond's rhubarb tuille.

Makes 6 with mousse left over


For the rhubarb and ginger purée

  • 400g forced rhubarb
  • 20g piece of ginger
  • 75g caster sugar

For the mousse

  • 4 leaves of gelatine
  • 60g liquid glucose
  • 120g caster sugar
  • 50g water
  • 120g egg whites
  • 350g whipping cream

For the pâte sucree

  • 250g type 45 flour [Buy] (or just plain if you have it)
  • 140g unsalted butter (softened)
  • 1 large egg
  • 1 large egg yolk
  • 40g ground almonds
  • 90g icing sugar
  • 1tsp vanilla extract

For the crème patissière

  • 250g whole milk
  • 1tsp vanilla paste, powder or essence
  • 3 large egg yolks
  • 37g caster sugar
  • 12g plain flour
  • 10g cornflour

For the white chocolate spray

  • 250g white chocolate coverture
  • 100g cocoa butter or groundnut oil
  • 1tsp red food colouring powder

For the rhubarb tuille

  • 1 stick of rhubarb
  • 2tbsp grenadine
  • 100g water
  • 20g caster sugar

To finish

  • Spring flower petals
  • Gold leaf


  • Silicone mat
  • Stand mixer
  • Thermometer
  • Spray gun (I use the Wagner W180P)
  • 6 inch diameter semi-sphere silicone mould (with 6 holes)
  • 6 inch tart rings

Note: there's some freezing and setting time involved here, so either start in the morning or the day before you want to serve them

Rhubarb and ginger purée

Chop the rhubarb into chunks, discarding any woody ends. Slice the ginger, then place both in a pot and cover with the caster sugar. Place over a medium heat, and watch as the rhubarb's juice starts to come out. Cook for about 5 minutes, stirring occasionally, until the rhubarb has broken down. Let it cool slightly to avoid burning yourself, then blend with a stick blender in the pot until you get a fine purée. Sieve it and set aside to cool a little more while you prepare the mousse ingredients.


Soak the gelatine in cold water for 5 minutes. When it's soft, squeeze out the water and mix it with the now slightly cooled purée (which should still be too hot to touch with your finger) from the first step. It won't set immediately, but carry on working quickly anyway.

Prepare to make the meringue - place egg whites into the bowl of your stand mixer with whisk attached. Put the caster sugar, liquid glucose and water in a heavy pot over a high heat and start to measure the temperature with your thermometer. You're looking to get to the magic 116 degrees centigrade - so, when you hit around 113, start your stand mixer up on the highest setting to whip the whites. When you reach 116, slowly pour the sugar syrup down the edge of the stand mixer bowl. Leave the mixer running at its highest speed until you get a thick Italian meringue.

Measure out your whipping cream, then whip until it leaves a trail on the surface of the cream.

Once the meringue is cool, pour in the purée and gently combine with a spatula, then do the same with the cream.

Take a 6 hole semi-sphere silicone mould, and spoon in the mousse. Try to make sure it coats the entire outer surface of each half sphere. When full, scrape the top of the mould with a spatula so that everything is level. Place the mould on a tray, and put into the freezer for at least 3 hours.

Rhubarb tuille

Pre-heat your oven to 100C.

Raymond used a vegetable peeler to make thin strips of rhubarb, but mine wasn't having any of it. If you also have trouble, just use a sharp knife to slice the stick of rhubarb as wafer thin as you can. Make as many as you can just in case they snap or fail. Place the strips into a heatproof bowl.

Place the grenadine, water and sugar in a saucepan and heat gently until it reaches a simmer, then pour this over the rhubarb. Leave for 10 minutes until cool.

Place a silicone mat on a heavy tray, then lie each thin piece of rhubarb spread out over that. Place it in the oven - mine took about 30 minutes, yours could take less or more time. Keep an eye on them. Alternatively you could use a dehydrator if you have one.

When the slices seem quite hard, remove from the oven to cool. When they've come to room temperature, they should be solid and crisp. Place into a sealed container and reserve for later. Don't put them in the fridge though!

Crème patissière

Pour the milk into a saucepan, add the vanilla and place on a medium high heat. Place the egg yolks and sugar into a bowl and whisk until a pale yellow colour. Next, add the flour and cornflour to the eggs and whisk again until you have a really smooth paste.

As soon as the milk is just about to boil, remove from the heat. Place your egg bowl on a tea towel to stop it moving, then pour a tiny amount of the hot milk over the yolks while you're whisking to temper them. Add a bit more milk, and keep on whisking, then add the rest, whisk for a moment, then pour the mix back in the pan over a more gentle heat.

Keep your whisk going gently, and you'll see it thicken within 30 seconds. Keep mixing, making sure it doesn't catch on the bottom of the pan. When it's very thick (about 60 seconds) pour it into a bowl and leave to cool. When cold enough, cover with cling film and put in the fridge.

Make, bake and fill the tart cases

Attach a whisk to your stand mixer, and add the butter. Whip until the butter has been creamed, then add the vanilla extract, icing sugar, ground almond and eggs. When combined, tip about 1/3 of the flour in. It should be combined in a few seconds, so repeat with the next 1/3 and then the final amount of flour. Stop the mixer when the mixture looks combined and a bit like wet sand.

Turn this out onto your work surface and press it all into a smooth ball. Place the ball on some cling film, then flatten slightly with the palm of your hand. Wrap it in the cling and place in the fridge for at least 2 hours.

When the pastry has rested, take your baking mat, place it on a tray, then the individual flan rings on top of that. Remove the pastry from the fridge and, working quickly, dust with icing sugar roll to a thickness of about 3mm. Try and make it as square as possible.

Cut the rolled pastry into 6 even pieces, then carefully - using an offset spatula, the rolling pin or carefully with your hands - lift, and unroll each piece over the rings. This is the part where disaster can strike, so try and start the unrolling with enough "edge" to cover the closest part to where you're standing. If it has worked, start pushing the dough into the edges of each ring, leaving any excess folded over the top. Don't trim it yet. If you find any cracks, just patch them with spare pieces of pastry or some of the edge overhang.

Turn your oven on to 170C.

To help stop shrinkage, freeze the tart cases instead of just putting them in the fridge. Leave the tray in there for about 30 minutes until nice and cold. When you're ready to blind bake, quickly remove the cases from the freezer and place some silver foil (matte side down) into into each one. Scrunch the foil down over the top edges of the cases so each one is completely covered in foil, then gently some baking beans into each one.

You need to add a bit of extra cooking time due to the frozen case, so bake for about 20 minutes. After this time it should look anaemic but be solid - so remove the foil and beans, then brush with a beaten egg and return to the oven for a further 5 minutes.

Remove and leave to cool for about 10 minutes, then use a sharp paring knife to trim the outer edge of each case. Carefully remove the rings, then brush out any pastry crumbs.

After they have completely cooled, take your crème patissière and spoon into each case. Use a spoon or palette knife to even the filling out. Place in the fridge to firm up.

Chocolate spray

Only start this when your mousse has completely set.

To prepare, cut 6 small pieces of greaseproof paper, large enough to hold each semi-sphere, but not much larger than that (or the paper will fold up during the spraying process and ruin the finish). Unmould each sphere onto the pieces of paper, then return to the freezer.

Get a cardboard box ready - a 12" record box is ideal (just ask your local hipster for one), but any box large enough for you to clearly see what you're spraying while containing the mist will be fine.

Place a metal bowl over a pan of simmering water and place the chocolate coverture into that. When it has completely melted, remove from the heat and add the red colouring. If you're using cocoa butter, melt it in a pan then blend - a 1/3 at a time - with the chocolate. If you're using oil, just fold it into the warm chocolate mix 1/3 at a time.

You'll end up with a nicely liquid mix - so pour that into your Wagner or similar spray gun.

Working quickly, take one semi-sphere out of the freezer, and place it in the bottom of the box. Stand 30 to 50 cm away from it, and spray into the box as straight as you can - be aware that if you tip the spray gun too far forwards you'll end up with air bubbles getting into the tube and you'll start spraying lumps at the mousse. Not good. Make a half , then spray again. If it doesn't look completely covered, turn and spray again. When you're happy, quickly return it to the freezer. Repeat with the other 6 mousses.

To construct

Take the filled tart cases out of the fridge, and the frozen sprayed mousse from the freezer.

Using an offset spatula, carefully slide under each mousse to release it from the paper then, wiping off any excess chocolate you've picked up, move it on top of the tart case. It should line up pretty much perfectly if you've used the mould sizes specified in the ingredients section.

Repeat this with the other cases and mousse semi-spheres.

If you're not ready to serve, place these in the fridge. When you're about an hour before serving, remove to allow the mousse to thaw out.

The gelatine in the mousse will hold it solid at room temperature, so you shouldn't have any issues with melting - but it's nicer if it's colder than room temperature.

When it has thawed a little, take a rhubarb tuille and push it into the side of the mousse. Decorate with a couple of petals and a bit of gold leaf. Repeat with the other desserts.

... then enjoy. Or not, if you hate rhubarb.

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