Passion fruit puree can be found in Latin grocery stores and online at amazon.com.

　　

Ingredients

Makes about 350 g (1 1/4 cups)

　　50 g passion fruit puree (1/4 cup)

　　40 g sugar (3 tablespoons)

　　1 egg

　　1/2 gelatin sheet

　　85 g very cold butter (6 tablespoons)

　　1 g kosher salt (1/4 teaspoon)

　　1 large grapefruit

　　3 g grapeseed oil (1 teaspoon)

　　

Step 1

Put the passion fruit puree and sugar in a blender and blend until the sugar granules have dissolved. Add the egg and blend on low until you have a bright orange-yellow mixture. Transfer the contents of the blender to a medium pot or saucepan. Clean the blender canister.

　　

Step 2

Bloom the gelatin (see page 29).

　　

Step 3

Heat the passion fruit mixture over low heat, whisking regularly. As it heats up, it will begin to thicken; keep a close eye on it. Once the mixture boils, remove it from the stove and transfer it to the blender. Add the bloomed gelatin, butter, and salt and blend until the mixture is thick, shiny, and super-smooth.

　　

Step 4

Transfer the mixture to a heatproof container, and put in the fridge for 30 to 60 minutes, until the passion fruit curd has cooled completely.

　　

Step 5

While the passion fruit curd is cooling, use a paring knife to carefully remove the rind from the grapefruit. Remove every last bit of it—leave no white pith behind! Then carefully remove each segment of grapefruit from its membranes by slicing down both sides of each segment, along the membrane, to the center of the fruit; the segments should come right out. (The technical term for this process is “suprêming” the fruit.)

　　

Step 6

Put the grapefruit segments in a small saucepan with the grapeseed oil and warm over low heat, stirring occasionally and gently with a spoon. After about 2 minutes, the warm oil will help separate and encapsulate the individual grapefruit “threads.” Remove from the heat and let the threads cool slightly before proceeding.

　　

Step 7

Using a spoon or rubber spatula, gently stir the grapefruit threads into the cooled passion fruit curd. Use immediately, or transfer to an airtight container and store in the fridge for up to 1 week.

　　

Notes

Step 8

Powdered gelatin can be substituted for the sheet gelatin: use 1/4 teaspoon.

　　Reprinted with permission from Momofuku Milk Bar by Christina Tosi with Courtney McBroom. Copyright © 2011 by MomoMilk, LLC. Published by Clarkson Potter, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.Christina Tosi is the chef and owner of Momofuku Milk Bar, called "one of the most exciting bakeries in the country" by Bon Appètit. As founder of the desserts programs at Momofuku, including Noodle Bar, Ssäat;m Bar, Ko and Má Pêche, Christina was most recently shortlisted for a James Beard Foundation Rising Star Chef Award. Christina and her confections have appeared on The Martha Stewart Show and Live! with Regis and Kelly, among others. She lives in Brooklyn, New York, with her three dogs and eats an unconscionable amount of raw cookie dough every day.