THE trick that anyone cooking tempeh should know is that you need to steam it before using it. Just steam it for a little bit before baking, or frying, or whatever and you’ll get rid of that sharp, almost chemical taste tempeh tends to have.
If you don’t want to use soy sauce because you don’t have it at home, you should go get a bottle at your local supermarket NOW. It’s so good. If you don’t want to use soy sauce because you just don’t like it, then oh well.
Tempeh is great with a chili sauce. Sambal goreng is the classic.
I normally cut it into triangles and lightly fry with mirin, salt, pepper and some soy but since half those are out, try frying it and adding it to a salad instead of whatever protein you would normally use. I’m biased though because I fucking love tempeh.