Private Cooking Lessons
Provision is highly variable. The major city nearest me has a comprehensive adult education programme which includes cookery courses over several sessions and single topic lessons. But where I live there's nothing provided by the local authority. When they do exist, these courses can be quite affordable. 

I have also come across a restaurant that doubled as a cookery school, but it closed last year. They tended to run one-off sessions but overall covered quite a range of foods, and there were sessions most weeks for a while. 

There's quite a range of cookery schools  in the UK, but these are often aimed more at people who want to be chefs than at enthusiasts. Some however (often based around a restaurant or hotel) run weekend residential courses on particular topics (for example the River Cottage). For a price of course, and not a small one. You can even combine this with a holiday to a region famed for its food, such as Tuscany, and learn to cook the local specialities. 

At perhaps the more accessible end of the market, I know of a major organic farm that currently runs single sessions but I'm sure has run courses in the past.