Brush mustard over tops of salmon; wrap salmon with prosciutto. Place, seam-side down, in a shallow pan lined with parchment paper.
In a bowl, toss tomatoes and olives (if using) with oil and basil; scatter around salmon. Bake until fish flakes easily when tested, about 15 minutes.
Meanwhile, in a saucepan, bring 1¾ cups (425 mL) water to a boil; stir in quinoa. Reduce heat, cover and simmer until liquid is absorbed, about 15 minutes. Remove from heat. Quickly add corn (do not stir in yet); cover and let stand for 5 minutes. Add green onions and stir.
Serve salmon and tomatoes overtop quinoa. Fresh basil makes a nice addition to scatter overtop, as does ground black pepper.
Per serving: 419 calories, 30 g protein, 12 g fat (1 g saturated fat), 49 g carbohydrates, 8 g fibre, 55 mg cholesterol, 178 mg sodium.