HEAT oven to 375°F.
COMBINE potatoes and half the Finishing Sauce; spread onto half of rimmed baking sheet sprayed with cooking spray.
MIX bread crumbs, nuts and half the onions. Dip fish in remaining Finishing Sauce, then in crumb mixture, turning to evenly coat both sides of each fillet. Place on baking sheet next to potatoes.
BAKE 20 to 25 min. or until fish flakes easily with fork. Meanwhile, stir-fry peppers and snow peas in Baking Sauce in skillet 2 to 4 min. or until crisp-tender.
SERVE fish with potatoes and pepper mixture. Sprinkle with remaining onions.