Step 1

Preheat broiler and set oven rack to about 6 inches below broiler element. Meanwhile, in a small bowl, stir together mayonnaise, harissa, lime zest and juice, and coriander seed. Season with salt and pepper; feel free to adjust flavor and heat level by adding more harissa, if desired.

Step 2

Line a rimmed baking sheet with aluminum foil. Lightly season salmon all over with salt and pepper. Set salmon on prepared baking sheet and rub a thin, even layer of harissa mayo all over the surface and sides.

Step 3

Broil salmon until browned on top and the center registers 115 to 125°F for medium-rare to medium, respectively, about 5 minutes; it can help to keep the oven door cracked while salmon is cooking to prevent the broiler from cycling on and off (though not all ovens function this way). If salmon becomes well browned on top before it is cooked enough in the center, switch off the broiler and set the oven to 425°F, then continue cooking until done (this shouldn't take more than 1 to 2 minutes longer).

Step 4

Transfer salmon to plates or a platter and serve.