Spanish Bacalao al Pil-Pil

Submerge the salt cod in a large bowl of cold water, skin side up. Refrigerate for 24–48 hours, changing the water every 8 hours (at least 3 changes). The fish is ready when a small piece, tasted raw, is pleasantly salty — like a lightly seasoned piece of fish, not aggressively briny. The flesh will have rehydrated and turned from stiff board to supple, with a pearlescent color. Cut into 150g portions. Pat completely dry.

In a wide, heavy skillet or earthenware cazuela, pour all the olive oil. Add the garlic slices and dried chilies. Over very low heat, slowly bring the oil to 60–65°C — use a thermometer; it must never boil or even simmer. Gently lay the cod portions skin-side up in the oil. Confit for 12–15 minutes at this gentle temperature, carefully turning once. The oil should show only the faintest, laziest movement around the fish — almost still. Remove the cod and set aside, reserving the oil.

Remove the garlic and chilies from the oil and set aside for garnish. Return the cazuela with the oil to the very lowest heat. Return the cod to the pan, skin-side down. Begin swirling the pan in a continuous circular motion, or use a flat-mesh spider to agitate the oil in circles around the fish. The gelatin released from the cod's skin will slowly emulsify with the oil over 8–15 minutes of continuous swirling. Do not stop or add any other ingredient. The sauce will gradually turn from translucent golden oil to an opaque, ivory-cream sauce — the pil-pil.