General Method Description

Butter is an essential ingredient in cooking many other items, especially baked potatoes with toppings. Churning is the only way to get butter in large quantities; it is easy to do but rather boring and slow. As in so many other cases, those two characteristics -- "boring" and "slow" -- are exactly why you can make money so easily by doing this activity. You also get a small amount of Cooking XP for your trouble.

Fortunately, while churning is dull, it's also dead simple: you just buy some cream and then churn it into butter. The best spot for this is Zanaris. Also, the very slow speed of the process makes this an excellent multitasking activity.

Note that there is no speed or other advantage to higher levels when churning butter, so the method is the same for mid, high and very high levels. Also, it would be possible to do this at lower levels, but I don't assume that anyone below mid levels will generally have finished the Lost City quest.