In a sauce pot, combine the water, salt, bay leaf, coriander seeds and the segmented lime and orange, and bring to a boil. Fill a separate large bowl with ice, water, lime juice and orange juice.
Once the water is boiling, add the scallops and let cook for approximately 2 minutes. Transfer the scallops to the ice bath and let cool. Once cool, dice the scallops into bite-sized pieces (approximately four pieces per scallop) and transfer to a glass bowl.
In a blender, combine the roasted serrano pepper, yuzu, rice wine vinegar, soy sauce and juice of 1 lime. Puree until smooth. Pour the marinade over the diced scallops then add the extra virgin olive oil, chopped cilantro and sea salt. Lightly toss and set aside for 30 minutes to let the scallops marinate.
In a food processor, add the avocado and lime juice and puree until smooth. Transfer to a mixing bowl, add the crema and mix well. Season with salt and pepper and set aside.
To plate: spread the avocado crema on the bottom of the plate, place about 4 tablespoons of the marinated scallops, then garnish with grapes, fennel, pickled onions, chives and cilantro.