There are quite a few good brands in the UK..buy a brand with the highest content of meat..and avoid those that contain wheat and corn..used in some dog foods as a cheap filler..they are the main cause of allergies in dogs.
I started off on Royal Canin because thats what the breeder was feeding Pixie...she did fine with this..the small sized kibble (Royal Canin Mini Junior) was great for Pixie's tiny mouth & teeth...she was only 1lb 7oz when I first got her!

some say Royal Canin can cause their babies skin to get itchy..maybe because it contains corn gluten? and I did notice Pixie would scratch a bit...wonder if anyone else feeding Royal Canin notices this too?
I'm now feeding two types of food..which seems to work well for Pixie..I leave down a bowl of James Wellbeloved kibble which she will pick at during the day and then at tea time she has the pouches of Natures Menu..I also buy their little bags of treats...heres their website..
Natures Menu Natural Dog Food & Natural Cat Food | Feeding as Nature Intended
Pixie also has other foods and treats such as..Natural yoghurt for brekkie..good for the digestive system..Goats milk,cereal such as cheerios...she loves cheese, eggs (scrambled & boiled) chicken, steak, fish...she also loves carrots & apples!