Blueberry & lime baked egg custard

Butter a 1-litre baking dish, then put the blueberries, half the lime zest and all the juice, the caster sugar and 150ml water in a saucepan and set over a medium-low heat until the sugar has dissolved and the blueberries have broken down a little. Remove from the heat. Combine the cornflour with 1 tbsp water and pour into the blueberry sauce. Bring to a simmer, stirring constantly until thickened.

Heat the oven to 150C/130C fan/gas 2. Beat together the eggs, condensed milk, soured cream, double cream and the remaining lime zest by hand or in a food processor. Pour the mixture into the baking dish, then put the dish in a roasting tin. Pour boiling water into the tin until filled halfway up the side of the dish, then bake for 50 mins-1 hr 10 mins or until the custard is set. It should wobble a little. Remove the dish from the tin and chill for at least 3 hrs. Turn the custard upside down onto a platter or serve in the dish with the blueberry lime sauce in a small serving bowl on the side.