Tempeh is basically just compressed, fermented soy beans (fermented is the only kind of soy that  I recommend).   It is an excellent source of vegetable protein and fiber.  For more info click here

I cut it into slices and pan fry it with some sort of sauce/marinade.   It will absorb and take on the flavor of whatever you fry it with.   Because it is so absorbant, I dilute the marinade with anywhere from 2 to 4 parts water.  Otherwise it will taste too much like the sauce.

Examples
1. Soy sauce, maybe some sesame oil, +/- ginger. ..Add a chunk of avocado with each bite…Awesome!!
2. Chicken wing sauce
3. Barbecue sauce