The en papillote method—baking fish in a packet to seal in moisture—is an almost foolproof way to ensure perfectly cooked fillets every time. The secret to this recipe’s tart, spicy, sweet sauce is chile crisp—a fiery hot-pepper condiment with plenty of crunch that can be found online or in specialty grocery stores. Quick-pickled shallots and cilantro in both the sauce and the garnish bring a bright finish.
Combine the shallot, vinegar, 1 teaspoon salt and the sugar in a small bowl. Cover and refrigerate while you prepare everything else.
Combine 2 tablespoons of the cilantro, the ginger, garlic, chile crisp, honey and fish sauce in another small bowl and stir into a thick paste.
Lay out 2 pieces of aluminum foil, each large enough to enclose a fish fillet in a packet, and place a fillet in the center of each. Sprinkle the fillets with the oil and season both lightly with salt all over. Coat both fillets with the chile crisp paste, making sure to cover all sides. Fold each piece of foil to enclose the fish, ensuring each is airtight. Place the packets on a baking sheet and bake for 10 to 15 minutes; when you open the packets, the fish should be opaque all the way through.
Unwrap the fillets and serve each topped with quick-pickled shallots and the remaining 2 tablespoons of cilantro.