Preheat oven to 400 degrees F. (See notes for grilling.): As the oven warms you will notice a dry, steady heat that primes the air for even baking, which is important for uniform cooking across the thick salmon fillet. This temp helps the exterior set without overcooking the interior, creating a tender center. A common mistake is not letting the oven fully reach temperature, which can lengthen cooking time and yield uneven doneness. If your oven runs hot, watch the first bake closely and trust the visual cues rather than time alone.
Line a large jelly roll pan with foil that extends 2” past the pan edge on each long side (so you can fold the sides up). Lightly spray foil with nonstick cooking spray. Place salmon in the center of the foil skin side down.: The foil creates easy cleanup and a shallow packet feel while the long overhang lets you fold the sides up for a snug perimeter. When you spray the foil lightly and place the salmon skin side down, the fish will sit on a stable surface and the spray prevents sticking. You should hear a faint sizzle if the pan is warm from the oven, that sound indicates moisture is starting to evaporate properly. Avoid folding the foil so tightly that steam is trapped against the top of the fish, which can prevent the top from browning during broiling.
Whisk all the Wet Rub ingredients together in a medium bowl. Pour rub on salmon and evenly rub all over the top. Fold up all the sides of the foil snugly around the salmon (but don’t cover salmon). Let salmon rest 15-30 minutes to come to room temperature (you can make the mango salsa during this time).: As you whisk, aromas bloom from the spices and citrus zest, creating a fragrant, slightly sweet mixture. Pour the rub on the salmon and rub evenly over the top; this ensures each bite carries the seasoning complexity. Letting the rub sit on the fish for 15 to 30 minutes brings the flavors together and allows the salt to begin flavoring the flesh. A frequent error is over rubbing so the spices clump; use gentle, even strokes and distribute the butter and honey so the paste is smooth and spreadable.
Bake salmon uncovered at 400 degrees F for 12-15 minutes (depending salmon thickness), then broil 3 minutes.: Folding the sides creates a raised rim that helps capture juices while leaving the top exposed for browning. You will feel the foil give and shape around the fish, which keeps it from sliding during transfer. This technique helps the fish steam slightly at first, retaining moisture, while the exposed top can finish with dry heat. Be careful not to pinch the foil flat over the top because that will block the direct heat needed for caramelization.
Garnish salmon with fresh lime juice and mango salsa. Season with salt to taste.: Allowing the salmon to lose chill makes for more even cooking, and you will notice the rub settle into the surface, intensifying aroma. During this time I often make the mango salsa , which saves hands on final assembly. A typical slip is skipping this rest, which can result in longer oven time and a drier center; patience here pays off with a juicier finish.
Bake salmon uncovered at 400 degrees F for 12 to 15 minutes: As the fish bakes you will watch the edges change from translucent to opaque and the surface take on a light golden sheen where the honey and butter begin to caramelize. The time depends on thickness, so use visual cues, pressing gently to feel firmness as a guide. Baking seals the fish and sets the top, preparing it for a short broil. Avoid opening the oven repeatedly, which drops the temperature and can extend baking time unnecessarily.
Then broil 3 minutes: The brief broil encourages a bronzed, slightly charred finish, and you might hear a soft crackle as sugars caramelize. Keep the oven door slightly ajar if recommended by your oven, and watch the color closely, because broiling can go from perfect to overdone quickly. A common mistake is walking away during broil, so stay attentive and remove the fish when the top is a deep golden brown with small bubbling spots.
Garnish salmon with fresh lime juice and mango salsa: Right before serving squeeze the additional lime juice to lift the flavors, and spoon the mango salsa across the top so the warm fish meets cool, bright fruit. The temperature contrast makes the salsa pop and gives each forkful an exciting range of textures. Avoid adding salsa too early, which can warm and lose vibrancy; add it at the last moment for the best contrast.
Season with salt to taste: After tasting a small piece, adjust salt so the flavors sing. A final pinch draws out the sweetness of the honey and the acidity of the lime, balancing everything on the plate. Over salting is easy, so add incrementally and taste as you go; if you do add too much salt, a squeeze more lime can help balance the impression.