Green Bean and Shiitake Tempura with Ponzu Mayonnaise

INGREDIENTS

• 1 large egg yolk
• 1 tablespoon red or white miso paste
• 1 tablespoon Kikkoman Ponzu Lime
• 1 tablespoon honey
• 1 cup vegetable oil
• Kosher salt
• 1 1/2 quarts peanut oil
• 1 cup unbleached all-purpose flour
• 1/2 cup rice flour (or cornstarch)
• 1 egg
• 1 1/2 cups ice cold seltzer water
• 1/2 pound green beens, trimmed
• 4 ounces (about 8 medium) shiitake mushrooms, stems removed, caps cut in half