HEAT oven to 400ºF.
CUT each potato into 6 wedges; place in large bowl. Add dressing; toss to coat. Place, cut sides down, on rimmed baking sheet sprayed with cooking spray. Bake 10 min.
MEANWHILE, mix cracker crumbs and 1 Tbsp. cheese in shallow dish or pie plate. Cut fish crosswise into 1-inch-wide sticks; spread tops and sides with mayo. Roll in crumb mixture until evenly coated.
TURN potatoes and move to edges of pan. Place fish, coated sides up, in center of pan. Bake 8 to 10 min. or until potatoes are tender, and fish is golden brown and flakes easily with fork. Sprinkle remaining cheese over potatoes.
SERVE fish with lemon wedges, broccoli and potatoes.