Heat oven to 425°F. Spray 11x7-inch (2-quart) glass baking dish with cooking spray. Cut halibut into 4 serving-size pieces. Place halibut in baking dish. Melt 1 tablespoon of the butter; brush over halibut.
In 10-inch nonstick skillet, melt remaining 1 tablespoon butter over medium-high heat. Cook potatoes in butter 5 minutes, stirring occasionally. Stir in lima beans and corn. Cook 3 to 5 minutes or until vegetables are crisp-tender. Spoon mixture around halibut in baking dish. Sprinkle halibut and vegetables with remaining ingredients; stir vegetables slightly.
Bake uncovered 20 to 25 minutes or until halibut flakes easily with fork and vegetables are tender.