This may come as a shock, but fenugreek leaves have a similar taste to maple syrup. It is sweet and slightly nutty when cooked. Some people have even compared the flavor of cooked fenugreek to that of burnt brown sugar. They add a huge depth of flavor to any dish they are included in.
If you choose to eat fenugreek leaves raw, they will have a much more bitter taste. The leaves are milder in flavor than the seeds and are commonly used in a similar manner to bay leaves.