Sift the flour with the potato starch and ground almonds. Work together with the butter and salt to form crumbs. Mix with the eggs and sugar using the paddle. Do not overmix. Refrigerate. Roll out to a thickness of 3 mm and cut out circles to fit into 4 Ø18 cm 2-cm high tart rings.
Wash the figs and cut in 2. Combine all ingredients in a sous vide pouch, seal and cook in a steam oven or a bain-marie for 20-25 minutes. Strain through a chinois. Remove the figs and set aside. Reserve the cooking liquid for the gelee.
Combine the softened butter with the icing sugar in the stand mixer. Add the ground almonds, custard powder and eggs. Pipe out into the pastry bases, top with the poached figs and bake for 35-40 minutes at 160°C.
Wash the tarragon, remove the leaves and blanch them in boiling water before plunging them into ice water. Strain. Heat the water with the glucose and the lemon juice, add the sugar combined with the agaragar and bring to the boil. Pour over the tarragon, add the zest and mix with a hand mixer. Strain through a fine sieve to obtain a very smooth gelee. Pour into a piping bag and refrigerate 24 hours.
Heat the water and sugar to 125°C. Deglaze with the fig cooking liquid then bring the temperature back up to 105°C. Add the gelatine mass. Let cool to 20°C. Pour over the figs using a piston funnel. Use 320 g of gelee per Ø18 cm tart.
Bring the cream (1), inverted sugar and glucose to the boil. Add the coarsely chopped fig leaves, cover the saucepan with plastic film and let infuse for 10 min. Strain through a chinois and pour over the white chocolate in 3 additions. Add the chilled cream (2) and mix. Refrigerate for 24 hours.
When the pastry base and the almond cream have cooked and cooled, pipe out a very fine swirl of tarragon gelee. Top with the previously unmoulded, glazed round of fig gelee. Pipe the fig-leaf Chantilly all around the edge of the tart using a plain 13-mm tip. Press down gently on the outside of each ball of Chantilly using a mini spatula to form even teardrop shapes. Decorate with a few leaves of tarragon.