In a large skillet or saucepan, saute onion and garlic in oil until tender. Add potatoes, seasoned salt, pepper and lemon zest. Remove from the heat. Spoon half into a greased 1-1/2-qt. baking dish. Sprinkle with 1 cup cheese. Repeat layers. Combine bread crumbs, butter and rosemary; sprinkle over cheese. Cover and bake at 400° for 40 minutes. Uncover and bake 20 minutes longer or until potatoes are tender.