I gotta be honest with you, I don't think there's a way to make tempeh taste really good. I reckon the best you can do is to mask it by smothering it in flavourful things but even then I still find myself preferring tofu over tempeh with the same preparation method.

I know this isn't a very helpful comment but sometimes there are foods which just aren't on the same tier as others and tempeh is one of those things in my opinion.

Fun fact though: tempeh is arguably the only fermented soy product that developed independently of all the other fermented soy products, which is kinda neat.