1. Position oven rack in upper third of oven; preheat broiler. Line a small baking pan with foil. Lightly oil foil or coat it with nonstick spray.
2. In a small dry skillet, toast sesame seeds over low heat, stirring constantly, until fragrant, 3 to 5 minutes. Set aside in a small bowl.
3. In another small bowl, whisk miso, mirin, soy sauce (or tamari), ginger and hot pepper sauce until smooth.
4. Place salmon fillets, skin-side down, in prepared pan. Brush generously with miso mixture. Broil salmon, 3 to 4 inches from the heat source, until opaque in the center, 6 to 8 minutes.
5. Transfer salmon to warmed plates and garnish with reserved sesame seeds, chopped scallions and cilantro (or parsley).