In a medium bowl, whisk together the Dashi, soy sauce, mirin, and yuzu. Taste and add more soy sauce, mirin, and yuzu as needed. Refrigerate until cold.
Dredge the botan ebi heads in cornstarch. Add enough soybean oil to a skillet to come about 1-inch up the sides and heat the oil until it's hot. Add the botan ebi heads and fry until golden. Transfer to a plate and set aside.
Combine the daikon sprouts and radish in a small bowl and toss with lemon juice, salt, and pepper, to taste. Divide the dashi mixture evenly among 8 soup plates. Garnish each bowl with a pinch of kombu, topped with a piece of uni, and then a pinch of shiso. Then make another pile of fat choy topped with 1 botan ebi and a fried botan ebi head. Add a few drops of yuzu juice on top and a pinch of scallion julienne. Make another pile with a little aka tosaka, topped with a slice of scallop, a dab of wasabi, and a bit of the daikon sprouts salad.
Rinse the kombu in cold water. Put the kombu in a stockpot with the water. Bring to a boil. Turn off the heat and add the bonito flakes. Let steep for 15 minutes and then strain through cheesecloth.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.