How to Make It
Whisk together orange marmalade, soy sauce, mustard, vinegar, crushed red pepper, 1/2 teaspoon of the salt, and 1/4 teaspoon of the pepper.
Preheat grill to medium-high (400°F to 450°F). Rub salmon with olive oil, and sprinkle with remaining 3/4 teaspoon salt and 1/4 teaspoon pepper. Place salmon, flesh side down, on oiled grates, and grill, covered, until mostly cooked through and skin is crisp, 7 to 8 minutes. Turn salmon, and brush with 1/3 cup of the marmalade mixture. Grill, covered, until a thermometer registers 140°F when inserted in thickest portion of salmon, 7 to 8 minutes. Place salmon on a platter, and brush with remaining glaze.