Uni Chawanmushi is a silky steamed egg custard gently set in a light, savory broth and topped with fresh sea urchin. Smooth, delicate, and refined, this dish delivers a subtle depth of flavor in every spoonful.
1. Prepare Kelp Broth: Make 5 cups kelp broth and allow it to cool completely.
2. Make Broth #1 (Sauteed Green Onion Broth) by sauteing sliced green onion in sesame oil until fragrant.
3. Add 1.5 cups kelp broth and simmer for 20 minutes, then strain and cool.
4. Make Broth #2 (Clear Green Onion Broth) by adding sliced green onion to 1.5 cups kelp broth. Simmer for 20 minutes, then strain and cool.
5. Combine Broth #1 and Broth #2 in a 1:1 ratio, and reserve 1.5 cups for the egg custard base.
6. Char 2-inch green onion sections.
7. In a saucepan, combine 1 cup kelp broth, mirin, soy sauce, and cooking wine. Add charred green onion and braise for about 20 minutes until tender. Reserve the green onion for plating.
8. Thicken remaining sauce with potato starch slurry until lightly glossy.
9. Prepare egg custard by gently whisking eggs without incorporating air.
10. Add 1.5 cups mixed broth, soy sauce, and mirin, and strain through a fine sieve.
11. Pour into heatproof bowls and cover tightly.
12. Steam gently over low heat for about 20 minutes, until just set (center should slightly jiggle).
13. Prepare Julienne the white part of green onion and fry until lightly crisp, to garnish.
14. Assemble: Place braised green onion vertically in the center of the custard, lay uni to the side, and spoon thickened sauce over the top.
15. Finish with fried green onion and enjoy!