This recipe for sea urchin with jalapeno and yuzu is courtesy of chef Gregory Brainin.
Source: The Martha Stewart Show, February Winter 2008
8 (1 1/2-by-1-inch) pieces black, rye, or sourdough bread
2 tablespoons cornstarch
1 cup yuzu juice
8 to 16 pieces sea urchin
1 small jalapeno, thinly sliced crosswise
Maldon sea salt
Lightly toast bread pieces until crispy on the outside but still chewy inside; butter one side of each piece of toast and set aside.
In a small bowl, whisk together cornstarch with 2 tablespoons water. Place 1/2 cup yuzu juice in a small saucepan and whisk in cornstarch mixture. Bring mixture to a simmer over medium heat. Remove from heat and whisk in remaining 1/2 cup yuzu juice. Pour yuzu mixture immediately into a bowl set in an ice water-bath. Let cool completely.
Top each piece of buttered toast with 1 or 2 pieces of sea urchin and a piece of jalapeno. Spoon over cooled yuzu mixture; serve immediately.