In a food processor, blend limes, EVO, serranos, cilantro until completely blended. Sprinkle with salt & pepper to taste. Set aside.
Lay out the radish, serranos, and green onions on the plate. Drizzle 2 tablespoons of the sauce on top.
Place the avocado on top, then layer the hamachi over it, slightly overlapping each piece. Drizzle the top with another 2 tablespoons of the sauce.
Sprinkle with masago and radish sprouts on top. Lightly sprinkle with sesame seed. Add a very light sprinkle of coarse salt and black pepper to top it off. If desired, drizzle more sauce or serve on the side.