Ingredients :
The Mona Lisa matcha cookie:
4 eggs
170 g almond powder
170 g icing sugar
7 g matcha tea
40 g flour type 55
140 g egg white
55 g caster sugar
35 g melted butter
Matcha syrup :
160 g sugar
250 g water
8 g matcha tea
Butter cream matcha :
40 g milk
one vanilla pod
1 egg yoke
40 g sugar
25 g egg white
50 g sugar
17 g water
150 g butter ointment
13 g matcha tea
Dark chocolate ganache...
200 g liquid cream
170 g dark chocolate (I used Valrhona Caribbean, 66% cocoa)
20 g butter
Decor and finish :
30 g dark chocolate
Cocoa powder
Matcha tea
Preparation :
The Mona Lisa matcha cookie:
Preheat your oven to 220°C.
Melt the butter.
Whisk together the eggs, almond powder and icing sugar. Add the flour and matcha tea and mix again.
To make a meringue, whisk together the egg whites, pouring in the caster sugar little by little.
Add the meringue to your first mixture, then with a maryse, mix gently from the outside to the center so as not to drop the egg whites.
Add the melted butter and mix again.
Spread your dough on two sheets, so that you can cut 2 rectangles of biscuit to the size of your mould on each sheet (you will need 4 rectangles in all).
Bake immediately so that your cookie does not fall back, for 8 to 10 minutes depending on your oven (you can switch your baking sheets halfway through).
Matcha syrup :
Bring water and sugar to a boil. Add the matcha tea once the syrup has cooled (to prevent it from cooking).
Butter cream matcha :
I'm not hiding it from you, it's not easy to make so little butter cream, think about scraping everything with a maryse to lose as little as possible.
Split your vanilla pod in half, scrape and add to milk. Bring to a boil.
Mix the egg yolk with the 40 g sugar, then pour the boiling milk on top. Mix and pour everything into your pan.
Cook the mixture again at 83°C (it is actually custard).
Pour it into the bowl of the mixer with the leaf and mix at low speed to cool the cream.
Make an Italian meringue. To do this, heat the 50 g of sugar with water in a saucepan to 118°C.
Mount your whites with a small electric mixer, then pour the cooked sugar while continuing to mix. It's not obvious from the quantity I grant you.
When the cream is cold, add the butter ointment (at room temperature). Once the mixture is homogeneous you can add the Italian meringue, then the matcha tea.
Set this cream aside while you do the rest, but avoid the refrigerator or you will have trouble spreading it in your assembly.
Dark chocolate ganache...
Bring the cream to a boil and pour it three times over the dark chocolate. Mix with a maryse every time you add cream.
Add the butter cut into pieces when the ganache is at 40°C. Mix again and set aside like butter cream.
Assembly :
Melt the 30 g of chocolate. Then chablonner one of the 4 biscuits. It is in fact a matter of spreading, using a brush, the chocolate so that it insulates the biscuit. The opera being a very wet cake, it is thus essential to be able to move it and to serve it correctly.
Then chablonné your cookie a few minutes in the refrigerator (or freezer to go even faster) to harden the chocolate.
Divide the syrup into 4 equal parts, each quarter of syrup will be used to soak a Mona Lisa cookie.
We begin the assembly: in your frame place your biscuit chablonné, chocolate side in contact with your plate. Then soak your biscuit with a quarter of syrup. You may feel there are too many, but the cookie will eventually absorb everything.
Then pour half of the ganache and spread with an angled spatula. Try to do something straight to get a nice cut.
Put down the second cookie and soak with the second quarter of syrup at the matcha.
Spread about 3/4 of your butter cream, you just need to keep some to make a thin layer on top of your opera.
Place the third cookie then soak it with the third quarter syrup.
Spread the second half of ganache.
Put down the fourth and last cookie and soak it with the rest of your syrup.
Finally, spread the rest of butter cream, film on contact so that the cream does not dry out. Reserve in the freezer (it is not essential but it facilitates the cutting).
For the cutting it is according to your desires and the size of your frame. I cut 10 small operas 10 cm long by 3 cm wide. You can also serve it whole, but in any case it is necessary to remove half a centimeter all around to obtain a clean visual and see well each layer of biscuit, cream and ganache.
Sprinkle with cocoa powder and a little matcha tea.
Remember to take it out of the fridge a little before serving. Having tested it, it is much better at room temperature.
Tips and Advice to remember :
Matcha tea tends to lump when used, so I recommend that you sift it. I use a small tea ball, very practical and well adapted to sift the matcha tea.
It is possible to prepare the Mona Lisa biscuit in advance. Simply film it and store it in the refrigerator to prevent it from drying out.
It is important that your custard is cold before adding the butter, otherwise it will melt. If on the contrary it is too cold and your butter seeds, pass your bowl quickly (a few seconds no more!) on a source of heat and mix again.
Remember to clean your knife between each cut of your opera to avoid ganache marks on the cookie.
