Lemon Blueberry Fruit Curd

Instructions

1. Prepare the specified fruit juice or seedless purée; strain out seeds, peel and fibrous solids to obtain the measured quantity.
2. In a heatproof mixing bowl thoroughly whisk the whole eggs and yolks together with sugar, salt and the measured cornstarch if used.
3. Whisk in all measured juice and fruit puree until fully blended, then pour into a heavy nonreactive saucepan.
4. Cook over medium-low heat, scraping the corners and bottom constantly, until glossy, thick enough to coat a spoon and 170–175°F (77–79°C). Do not let the curd boil hard.
5. Immediately strain through a fine sieve to remove cooked egg bits, then whisk in cold butter a few cubes at a time until fully emulsified.
6. Transfer to a shallow clean container; apply food-safe film directly to the surface and chill promptly to 40°F (4°C) or colder.
7. Allow at least 4 hours in the refrigerator to finish thickening before using for tarts, cakes, biscuits or pastry fillings.