The cardamom creme patissiere can be made in advance and stored in the fridge for up to 3 days.
Bash the cardamom pods with something hard like the bottom of your saucepan to split the shell slightly. Bring the milk and cardamom pods to a boil in a saucepan over a medium heat.
Remove from the heat and leave to cool completely.
Meanwhile combine the sugar and flour in a medium bowl. Add the egg yolks and whisk until the sugar is combined and you have a pale mixture.
Sieve the cooled infused milk to remove the cardamom pods and any seeds. Heat the milk again until it comes to a boil.
Whisk a third of the milk into the egg mixture to loosen it. Whisk in the remaining milk and return the mixture to the saucepan, cook over a medium heat, whisking constantly.
As soon as the pastry cream begins to thicken, keep cooking it over the heat for a minute or two to cook off the flour.
Scrape the pastry cream into a bowl and cover with a layer of clingfilm, pressing it down so it touches the surface of the cream. This will stop a skin forming. Allow to chill completely.
To make the mango filling, peel, pit and cut the mango into 1cm cubes.
Warm the honey in a frying pan over a medium heat, add the diced mango and lemon juice.
Cook, stirring occasionally until the mango is evenly coated, this should take about 2 minutes.
Transfer to a bowl and leave to chill.
To make the macaron shells, preheat the oven to 170C Fan/190C and line two baking trays with baking parchment. Draw two 20cm circles on the reverse of the baking parchment to help with the piping. Also draw 20 smaller circles on another piece of baking parchment, with a diameter of 5cm. You may not use them all.
Grind the ground almonds and icing sugar together in a food processor and then sift them into a clean bowl that is quite large. This is necessary to make sure your macaron shells are nice and smooth.
Add 75g of the egg whites to this mix and beat it, until it forms a paste. Leave to one side while you make the meringue.
Add the water and granulated sugar to a pan and stir over a medium heat until the sugar dissolves.
Put half of the egg whites into a stand mixer and whisk them on a medium speed until frothy.
Bring the syrup to a boil and heat until it reaches 121 degrees.
Pour the syrup in a slow steady stream into the egg whites as they are being whipped on a medium speed. Keep whipping until the meringue forms a stiff peak and the side of the bowl feels cool - around 5mins.
Add the food colouring and mix through until you have a nice orange shade.
Add a third of the meringue to the almond paste and beat it in thoroughly to loosen the paste.
Fold through the remaining meringue, ensure the ingredients are mixed thoroughly. Keep mixing until the mixture is looser and falls from the spoon quite easily, be gentle though, don't overmix or beat it harshly.
Put the macaron mix into a piping bag and pipe out the two circles working in a spiral from the centre, don't bang the tray as you want to keep the spiral shape.
With the remaining mix pipe out the small macarons until you have used it all up.
Place the large macarons in the oven for 20mins. Turn the trays halfway through cooking to ensure an even bake.
Then cook the smaller macarons for 10mins, rotating the trays halfway through cooking. Let the cooked macarons cool completely before trying to remove them from the tray. This helps to stop them sticking.
To make the cardamom creme mousseline, take the chilled creme patissiere out of the fridge about 30 mins before you want to use it, if it's too cold the butter wont blend with it.
Place it in the bowl of a stand mixer fitted with the paddle attachment. Give it a mix to loosen it up and with the mixer running the whole time, slowly add the butter bit by bit so you have a soft fluffy cream almost like a buttercream.
Place the cardamom creme mousseline in a piping bag with a round nozzle about 1cm fitted and pipe a layer of the cream on the bottom macaron shell in a spiral pattern, then pipe a ring around the outside edge and fill the inside with the mango (remember to reserve some mango for your smaller macarons and for decoration). Pipe a small amount of cream on top and then lay the other shell on top gently so they don't crack.
Take the small macaron shells and pair up even sized shells, pipe a ring of cardamom creme mousseline on the base and fill it with the mango filling. Place a shell on top and place these in the fridge.
Place the macaron cake in the fridge and allow it to set for at least a few hours before you eat it, as the shells will absorb the flavours.
Don't place the remaining cardamom creme mousseline in the fridge as it will set too hard to pipe.
To decorate the macaron cake do this just before serving or the shell will absorb the moisture and go soggy. Pipe small blobs of the cardamom creme mousseline on top and place a piece of mango on top. You can then use gold leaf or tempered chocolate decorations to finish it off.