In the freezer section today I spotted Asda Sweet Chilli Prawn Skewers reduced to clear at 50p per box. These are tail-on prawns marinated in sweet chilli sauce, on bamboo skewers, four skewers per box, and are really nice.
Might not be in all stores but there were absolutely loads in my local Asda so it's possible other stores will have them.
There's lots of other frozen barbecue items and lots of desserts reduced to 50p as well in the freezer section. Worth looking out for.