4 tablespoons unsalted butter
½ teaspoon red-pepper flakes
1 ½ teaspoons orange zest
3 tablespoons finely chopped mint
Kosher salt and black pepper
4 (5- to 6-ounce) salmon fillets
Flaky salt, for serving (optional)
Turn on the broiler and position the oven rack to sit about 6 inches below it.
In a small saucepan, melt butter over medium-low heat. Add red-pepper flakes, and cook for about 1 minute. Remove butter from heat, and stir in orange zest and 2 tablespoons mint. Set aside.
Season salmon well with salt and pepper and place skin-side down on a rimmed baking sheet lined with foil. Spoon butter mixture evenly over the top of each fillet.
Broil salmon for 4 to 6 minutes until the skin becomes opaque and the fish appears flaky. It should be medium-rare in the thickest part of the fillet. If you prefer your salmon a bit more cooked, leave it in for another minute or so, moving it to a lower rack if the tops get too dark. Serve, and scatter with remaining mint. Season with flaky salt, if desired.