Place miso, yogurt, lemon juice, sesame oil, salt and pepper in a small mixing bowl and whisk together.
To assemble: Scoop a small amount of the sauce onto one end of a plate and drag across to the other end. Top sauce with a piece of scallop followed by uni and repeat until 1 scallop has been used. Repeat on another plate with the remaining sauce, scallop and uni. Top each crudo with a small amount of tobiko and arrange radishes, serranos and micro amaranth around. Finish with a drizzle of extra virgin olive oil and serve.