I began by preparing all the ingredients: slicing the asparagus into .5"-1" lengths on the diagonal, slicing the onions into rings, separating the chard leaves from the stem (to be used in something else) and chopping them thin, and scrambling the eggs with the salt, pepper, all but 1 tbsp cheese. I heated my smaller cast iron pan(though if your serving more than one and a mouse you might want to go for the big pan) over medium heat and let the butter melt. I love the smell and character of real butter compared to the commercial stuff; it cooks differently. First the onions and chard went into the pan at the same time, stirring constantly. It will reduce down by about half.
After about 5 minutes, when the onions were almost starting to caramelize I tossed in the asparagus and gave it a good mix. I let it go another 5-7 minutes, stirring occasionally, to let everything get cooked through without losing the bright green color. It was about now that I remembered to turn on the broiler. Then I added the eggs and gave everything a good quick stir to get the egg mixed in before it started to cook and stick.
It continued to cook on the stove top until the top was almost set. I use the giggle test--shake the pan and if the bits move it needs more time, if only the top most bits move it needs a very little bit more time and the second the top bits stop moving its ready to be moved--as the top of the egg should look moist even when it is nearly set. If you wait until the top starts to look dry or set then you'll likely get a little too much brown on the bottom. If you move it too soon you may get undercooked areas in the center and in between the vegis--eeewww.
Sprinkle with your cheese. I used Parmesan for flavor without lactose or lots of extra calories but I seem to remember that many cheeses go well. Next I placed the pan under the broiler for 3-4 minutes to get the top to cook, the cheese to melt and to get a beautiful golden brown color.