A firm white fish works best in this halibut recipe to stand up to the heartiness of the sautéed peppers, garlic and capers, but you can substitute any white fish including swordfish, mahi mahi or sea bass.Try to find a variety of colors for the peppers to create a stunning finished dish, and don’t toss with the basil until just before serving to keep its bright green color and fresh taste. Serve with a warmed baguette for sopping up extra juices from those peppers—and enjoy!