I love mushrooms!!! If you want to do a low fat "healthy" stir up to serve as a side with a steak or burger (or chicken or pork for that matter.) I'd start them with a touch of olive oil (and I mean a touch) and sauté them so they exude their juices. You can season them with salt, pepper, garlic powder or add thinly sliced onion or garlic (add garlic towards then end so it doesn't burn). If you have any wine open, you can add a quick pour, or stock or even soy sauce.
Mushrooms are easy to "glam" up!
Oh, and if you feel decadent---cook them in butter
Beef stroganoff (or vegetarian stroganoff where you only use mushrooms, yum!), add to spaghetti sauce, or my favorite...thinly sliced steak with sautéed bell peppers, onions and mushrooms. Either put on a hoagie with provolone cheese, or pile the mixture on a baked potato split in half and top with provolone (really delicious).
I looooove mushrooms!
By the way, I use recipes for the stroganoff and philly baked potatoes from Skinnytaste.com which are healthy versions.
I like sauteed! If you're cooking them up for many people you can use a bit more oil and even butter, because it doesn't take much and the calories are spread among everyone sharing it.