The gingernut-fresh basil crust is delightfully unusual, as is the whole cheesecake to be honest. I suggest that you’ll probably want to make double the amount of the tomato jam: it’s really good for a variety of other things, like a cheese plate.
Crush the biscuits and mix with the melted butter, sugar, and basil; press into the bottom of a cake or pie dish, and place in the refrigerator to chill while you prepare the filling.
For the ricotta filling:
Break up the ricotta in a mixing bowl, and beat in the egg yolks and whole eggs, then add the cream, sugar, lemon zest or extract, and salt.
Pour over the chilled crust, and bake in a 175 °C oven for about 20 minutes or until the cheesecake turns golden on top and is slightly set. Remove from the oven and leave to cool while you make the topping.
For the topping:
Combine the passata with half the water, the sugar, the celery and the salt. Bring to boil, then reduce heat and simmer 10-15 minutes or until the celery softens; add more water if it gets too thick and threatens to scorch.
Meanwhile, sprinkle the gelatine over the remaining water and leave about 5 minutes until it is softened, and thickened.
Strain the tomato sauce, pressing the celery to extract as much of the celery flavour as you can; discard the solids. Add the softened gelatine to the tomatoes, mix well and cook over a medium low heat until the gelatine dissolves completely.
Pour the strained tomato mixture over the cheesecake, tilting the pan so that the tomato layer is thin and even. Place in the refrigerator and chill until ready to serve.
Serve with Caramelized Tomato Jam
In a heavy-bottomed saucepan place the sugar in an even layer. Cook over a medium low heat until the sugar begins to melt and colour. Add the whole tomatoes from the can, reserving the juice; break the tomatoes up with a wooden spoon as you cook them. You want the jam chunky.
When they are slightly browned here and there, taking care that the sugar does not burn, add the juice that the tomatoes came in. Cook together, stirring every so often, until the tomatoes have concentrated to a thick, jammy consistency; about an hour.