Place dried scallop and shrimp in separate containers and pour over boil hot water. Just enough to cover. When soft, set aside liquid and chop or grind in a mortar and pestle. Slice prosciutto into like-sized pieces. Set everything aside.
Mince garlic, chile, and slice prunes and shallots thin.
Saute garlic, chile, and shallots, add rest of ½ cup oil and bring up to temp. Add scallops, shrimp, prosciutto and prunes. Saute/shallow fry for 3-4 minutes. Add the liquid from reconstituting the shrimp and scallops. Add more oil if the ingredients aren’t covered. Cook down on a simmer 45 min-1 hr low and slow. This sauce is meant to be oily. Don’t be afraid. It’s like a chunky umami chile oil.
Slice into the fish slightly at an angle. Season the outside of the fish with salt and dredge with tapioca starch. Fry at 350 F until golden brown and cooked through. Serve with Thai basil and white rice.