How to Make It
Preheat grill to medium-high (400°F to 450°F). Brush salmon fillets evenly with 1 tablespoon of the oil; sprinkle with pepper and 1 teaspoon of the salt. Place salmon on oiled grates; grill, covered, until slightly charred, about 4 minutes per side. Transfer to a platter.
Whisk together lemon juice, parsley, shallot, mustard, and remaining 1/4 cup oil and 1/4 teaspoon salt in a small bowl; drizzle 3 to 4 tablespoons vinaigrette over salmon. Serve salmon alongside remaining vinaigrette.