Fasts should be broken with high water content raw foods. Fruits are usually the best thing, they are easily digested which is important after the digestion system has had a break and the water in them cleans the digestion system rather than irritate or clog it. The longer you can just eat raw fruit the better, at least the first couple of days depending on how long your fast was, then adding other raw vegetables and maybe small quantities of raw nuts. The Refeeding period is said to be about the same amount of days as the fast was, so it's best to stay mostly raw until that is over.
The first few days, maybe the first week after a long term fast, are the most crucial. Eating the wrong foods or too much can overtax the partially shutdown digestion system and cause great harm to the body. To get the most out of your fast, and to ensure it remains a safe fast, always break your fast carefully.