1 x 500 ml tub creme fraiche
1 x 500 g tub Greek yoghurt
1 x 11 g sachet gelatine powder
1 oz (25 g) golden caster sugar
a little flavourless oil, such as groundnut or grapeseed, to oil the jelly mould
For the compote of blueberries in Marsala
1 lb (450 g) blueberries
10 fl oz (275 ml) Marsala
3/4 oz (20 g) golden caster sugar
1/2 cinnamon stick
1 teaspoon vanilla extract
1 rounded teaspoon arrowroot
You will also need a 2 pint (1.2 litre) jelly mould or 6 individual pudding pots of 6 fl oz (175 ml) capacity, and a shallow baking dish about 8 x 6 inches (20 x 15 cm).
To enable you to turn the dessert out as easily as possible, begin by lightly oiling the inside of the mould or little pots. Then place 4 tablespoons of cold water in a small bowl, sprinkle in the gelatine and leave it aside for 5 minutes to soak. After that, place the bowl in a saucepan of barely simmering water and leave it until the gelatine has completely dissolved and you are left with a clear liquid. This should take about 10 minutes, but be careful not to let the water boil.
While that's happening, place the creme fraiche, yoghurt and sugar into a large bowl and whisk, preferably with an electric hand whisk, until the mixture becomes floppy. Then fold 2 tablespoonfuls of this into the dissolved gelatine and, as quickly as possible, fold the gelatine mixture into the rest, stirring and folding everything to make sure it is thoroughly amalgamated. Now pour the mixture into the mould or pots, cover with clingfilm and then leave it in the refrigerator overnight to set.
Like the dairy cream, the blueberry compote is best made the day before to allow all the flavours to develop. First pre-heat the oven to gas mark 4, 350 F (180 C). Then all you do is place everything except the arrowroot into the shallow baking dish, place it on the centre shelf of the oven, without covering, and leave it there to cook for 40 minutes.
After that, mix the arrowroot with a little cold water in a small saucepan, and strain the juice from the cooked blueberries in as well. Then place the saucepan over a gentle heat and whisk until it comes back to a simmer and thickens very slightly. Now remove the cinnamon stick and pour the liquid back over the blueberries. Allow them to cool, then cover and chill in the refrigerator till needed.
To serve, if you are using a jelly mould, gently loosen the cream from the edges using your fingertips, then invert a plate on to the base, turn the mould upside down and give it a hefty shake. If that fails, dip the mould briefly into hot water to loosen it. If you are using smaller moulds, they should turn out very easily. Then serve the cream with the blueberries handed round separately.