I sauteed the mushroom in butter, salt and pepper. They were delicious by themselves.
With the jalapeno I made the mistake of seeding it. It was super bland.
I added the mushrooms and jalapeno to the pan almost immediately after I added the whisked egg.
There's been a bunch of good ideas in this thread and the video of the guy making a Jacques Pepin omlette is great. I definitely have some new ideas for my next attempts.