Heat 2 teaspoons oil in a large skillet over medium-high heat. Add onion, garlic, and bell peppers; sauté 5 minutes. Add broth and next 4 ingredients. Bring to a boil; boil 1 minute. Spoon pepper mixture into a 13- x 9-inch baking dish. Wipe skillet with a paper towel.
Heat remaining 2 teaspoons oil in skillet over medium-high heat until hot. Add bass; cook 2 minutes. Remove fillets from skillet; place on top of pepper mixture, browned side up. Bake at 450° for 8 minutes or until fish flakes with a fork. Serve fish with potatoes topped by Red Pepper Rouille.