Lakeland 20 Fish Cook-in-Bags 5 "Brilliant!" Miss Spillar 22 June 2020 I have used these bags for years. They are so simple to use, and leave you with a clean baking tray!! There is no need to add butter/spread to the fish, as there will be the fish liquid in the bag as it cooks. A great time-saving purchase which results in very moist and tasty fish. Highly recommended.