Preheat oven to 425°F. Line a 15x10-inch baking pan with foil; lightly coat with cooking spray. In a large bowl combine 1 Tbsp. of the oil, the onion powder, 1/4 tsp. of the garlic salt, and 1/4 tsp. of the pepper. Add potato wedges; toss to coat. Arrange in a single layer on half of the prepared baking pan. Bake 15 minutes. Meanwhile, in a small bowl combine bread crumbs, thyme, and the remaining 1/4 tsp. garlic salt and pepper. Add the remaining 2 Tbsp. oil; toss to combine. Remove baking pan from oven. Carefully turn potatoes over. Place fish on the other half of the hot baking pan. Sprinkle crumb mixture onto fish; return to oven. Bake about 10 minutes more or until potatoes are tender and starting to brown and fish flakes easily. Serve with lemon wedges or malt vinegar.