HEAT oven to 425ºF.
TOSS potatoes with oil; place, cut sides down, on half of parchment-covered rimmed baking sheet. Bake 20 min.; turn potatoes.
SPREAD asparagus onto other side of baking sheet; bake 5 min. Meanwhile, place fish on separate parchment-covered baking sheet; brush with 2 Tbsp. dressing.
ADD fish to oven with vegetables. Bake 10 min. or until potatoes are tender and fish flakes easily with fork. Drizzle remaining dressing over vegetables; toss to coat. Top with cheese. Sprinkle parsley over fish; serve with vegetables and lemon wedges.