Hi Sue, sorry I can't help you with locating UK freeze-dried raw food brand, but here are two of the more popular brands in the USA. Perhaps you can compare the ingredient list with something you find in the UK as these two brands have been on the market for a while.
1. Small Batch Freeze-Dried. This is the one I have bought for years now and what cured my dog with severe skin issues (and extreme fur loss) Check out the ingredient list on the website for chicken as an example. They make frozen patties and freeze-dried.
2. Stella and Chewy: One of the first to market in the US with raw food for dogs and cats.
3. Newer on the market but with very positive feedback: Open Farm
Hope this helps! Let us know how it goes.