Heat oven to 350 F and line baking sheet with parchment paper or lightly oiled foil.
To make honey-lemon marinated grapes: In medium bowl, whisk oil, lemon juice, honey, basil, salt and pepper, to taste. Stir in grapes, onion and arugula; set aside.
To prepare salmon: In small bowl, stir walnuts, sunflower seeds, honey, mustard and salt until thick paste forms.
Place salmon on prepared baking sheet, skin side down, and press equal amounts walnut mixture over surface of each. Bake 20 minutes, or until salmon flakes easily with fork.
Set salmon on plates; using slotted spoon, spoon marinated grape and onion mixture over salmon and around plates.
Notes
Nutritional information per serving: 640 calories; 39 g protein; 31 g carbohydrates; 41 g fat (58% calories from fat); 7 g saturated fat (10% calories from saturated fat); 95 mg cholesterol; 390 mg sodium; 3 g fiber.