Here's a list of businesses (and their ratings) in the Mobile caterer category.
In England, Wales and Northern Ireland food hygiene ratings are provided by the The Food Hygiene Rating Scheme (FHRS). Ratings in Scotland are provided by a similar scheme called the Food Hygiene Information Scheme (FHIS).
You can read more about FHRS and FHIS food ratings here.
Click on a establishment below for more information:
Archway Waffle Hut, Kiosk 707 Outside, 14 Junction Road, London

Total Score: 25 (lower is better)
Arsenal Kiosk, 138 Gillespie Road, London, N5 1LP, N5 1LP

Total Score: 15 (lower is better)
Caffe Mobile, York Arcade, 80 Islington High Street, London

Total Score: 0 (lower is better)
PERFECT HYGIENE RATING SCORE
Chai n' Biryani & Udyan, Unit 26 and 27 Nags Head Covered Market, 22 Seven Sisters Road, London, N7 6AG

Total Score: 20 (lower is better)
Cyprus Kebab House, Unit 16 and 17 Nags Head Covered Market, 22 Seven Sisters Road, London, N7 6AG

Total Score: 25 (lower is better)