Tuna Tatsuta-age with Bright Green Cucumber Dressing from The Sushi Experience by Hiroko Shimbo

Ingredients

• 1 tablespoon dashi (fish stock)
• ½ teaspoon sugar
• 1 teaspoon umeboshi paste (salt-pickled plum)
• 1 small daikon radish (3½ ounces)
• ½ teaspoon salt
• 2 Japanese cucumbers (7 ounces) or 2 Kirby cucumbers
• Vegetable oil for frying
• ¼ cup potato starch
• ⅔ pound sushi or sushi-grade maguro (tuna), cut into large cubes or into slices 2 inches square x ½ inch thick
• 2 tablespoons mirin (sweet cooking wine)
• 2 garlic cloves, grated on a very fine grater or crushed in a garlic press
• 2 teaspoons vegetable oil or olive oil
• ½ teaspoon komezu (rice vinegar)
• 2 tablespoons shoyu (soy sauce)
• 2 teaspoons freshly squeezed ginger juice from grated ginger