- Refrigerate the cans of coconut milk for at least 8 hours.
- In a small pot off the heat, whisk together the sugar and cornstarch. Add the eggs and egg yolks. Mix well. Add the grapefruit juice. Bring to a boil over medium heat, stirring constantly and scraping the bottom and sides of the pot, until thickened. Remove from the heat. Add the butter. In a sieve set over a bowl, strain the cream to remove any lumps, if needed.
- Divide the cream among twelve 1-cup (250 ml) jars. Cover and refrigerate for 2 hours or until completely chilled.
- Meanwhile, with the rack in the middle position, preheat the oven to 350°F (180°C). Line a baking sheet with a silicone mat or parchment paper.
- In a bowl, combine all of the ingredients until just moistened. Press the mixture together with your hands, letting it fall in pieces of varying size onto the baking sheet.
- Bake for 15 minutes, stirring halfway through. Let cool completely on the baking sheet.
- Break 36 meringues into large pieces. Set aside.
- Cut the top and bottom end off each grapefruit. Sit the grapefruits flat on a cutting board. Cut off the peel, getting as close to the flesh as possible. Make sure to remove all the white pith. Slide a knife between the membranes to remove each segment (suprême). Cut each segment in half. Set aside.
- Open the cans of coconut milk upside down. Separate the liquid from the solids. Set the liquid aside for another use. Place the solid coconut milk and sugar in a bowl. Beat with an electric mixer until creamy and resembles whipped cream.
- Sprinkle the coconut crumble over the grapefruit cream in the jars. Add a layer of the coconut cream. Top with the broken meringues alternating with pieces of grapefruit. Top each jar with a full meringue and sprinkle with lime zest.
We used Thai Kitchen brand coconut milk. This brand gave us the largest quantity of coconut cream and, therefore, the best result. Depending on the brand you choose, the quantity of coconut cream will vary. Certain types of coconut milk (such as low-fat varieties) will not become solid when refrigerated and will not work for this recipe.