1: Prepare a confectioner's custard: pour 250 ml milk into a pan, add the ½ vanilla pod and bring to the boil. As soon as the milk boils, add the zest of 1 lime. Remove from the heat, cover and leave to infuse 10 minutes.
2: Prepare the custard by mixing together 50 g caster sugar and 3 egg yolks, then add 20 g cornflour and mix thoroughly. Pour the hot milk onto this mixture and stir constantly until thoroughly mixed. Then pour it back into the pan through a sieve to remove the vanilla and lime zest.
3: Cook as for a normal confectioner's custard, then stand the pan to cool in cold water, stirring occasionally to avoid a skin forming. When the custard is still warm, add the juice of 1 lime and 4 drops food colouring (green), and beat vigourously. Leave to cool completely, still with the pan in cold water.
4: Meanwhile, prepare or thaw 300 ml blackcurrant coulis, which should be completely smooth in texture.
5: Mix 20 g caster sugar with 2 g agar-agar. This is to help the agar-agar blend more easily with the syrup.
6: Bring 200 ml sugar syrup to a simmer and tip in the mixture of sugar and agar-agar while beating vigourously to mix.
7: Then pour the hot syrup into the blackcurrant coulis and mix well. You can use a hand-mixer briefly for this if you wish, to ensure thorough mixing.
8: Begin assembling the verrines by putting a layer of cold (or barely warm) confectioner's custard in bottom of each glass. Use a forcing bag if possible, as this makes the job much easier.
9: Pour a layer of blackcurrant coulis on top while this is still warm and sufficiently runny.
10: Finish with a layer of whipped cream (chantilly), which you can dust with a little matcha green tea powder.
Remarks
If you wish to prepare the dessert in advance, this is not a problem for the 2 layers of lime and blackcurrant, but it's wise to prepare the whipped cream at the last minute; it's always better.