XO sauce

Directions

1. Peel the shrimp, discarding their shells.
2. Using paper towels, blot the shrimp and scallops until dry and tacky. Cut the shrimp in half lengthwise, removing the dark blue vein down the back as you go. Slice the scallops horizontally so each is in 4 thin rounds.
3. Transfer the seafood to a small mixing bowl and, using your fingers, combine it very thoroughly with the salt.
4. Lay the sliced and salted seafood in a single layer atop a large, clean kitchen towel and lay another one on top. Cover the top towel with a board and weight which combine to equal about 5 pounds. Let the seafood press at room temperature for 3 hours.
5. Meanwhile, ready a wire rack over a rimmed baking sheet and cover it with a thin sheen of vegetable oil. As the 3-hour drying period comes to a close, move an oven rack to the lowest position and preheat the oven to 200 F. Lay the pressed seafood on the rack in a single layer. Place the seafood in the oven and prop the door ajar with the handle of a wooden spoon. Let the seafood dry for 1 1/2 to 2 hours. The edges of the scallops will be slightly brown, and all of the seafood will be dry and leathery, but not stiff.
6. Now it's time to make the sauce. In a food processor fitted with a metal blade, mince the garlic and ginger until they stop whirling inside the machine. Add the chiles, shrimp and scallops, prosciutto, and sugar and process until very fine, running the machine about 1 to 2 minutes and stopping to scrape down the edges of the bowl as needed.
7. Scrape the entire contents of the food processor bowl into a medium skillet, add the vegetable oil, and stir to combine. Place the pan over medium heat, and once the mixture starts to sizzle, lower the heat as needed to keep it bubbling, but not splattering. Stir it frequently, scraping up the solids from the bottom, until the sauce becomes very dark coffee brown all over, about 13 to 17 minutes. Take the pan off the heat and stir to cool slightly. Once the bubbles have subsided, add the soy sauce and sesame oil and stir to combine.
8. The sauce is ready to use right away, though it will become even better after you allow the flavors to meld for a day. Scrape the sauce into a container with a tight-fitting lid and let it sit at room temperature for 1 day before refrigerating. The sauce will keep at least 3 months refrigerated, and several months in the freezer.