To prepare pesto, combine first 4 ingredients in a food processor; process until smooth. Add cheese and red pepper; process until blended. Transfer mixture to a bowl. Add tomato, 1/2 teaspoon salt, and black pepper, stirring gently to combine.
To prepare fish, sprinkle fish with 1/4 teaspoon salt. Arrange fish on a broiler pan coated with cooking spray, and broil 8 minutes or until fish flakes easily when tested with a fork. Place 1/2 cup orzo on each of 6 plates, and top each serving with 1 fillet and 1/4 cup pesto.