Cook the quinoa according to the package directions. Toss with the snap peas, scallions, 2 tablespoons of the oil, ½ teaspoon salt, and ¼ teaspoon black pepper in a large bowl.
Heat broiler. Pulse the roasted red peppers, the remaining 1 tablespoon of oil, orange zest, vinegar, crushed red pepper, and ¼ teaspoon each salt and black pepper in a food processor until smooth.
Place the fish on a rimmed baking sheet. Spread the red pepper mixture, dividing evenly, over the fish. Broil until opaque throughout, 6 to 8 minutes.
Serve the fish with the quinoa salad. Sprinkle with the cilantro.