Indoors. I have a pan, or an oven. And plenty of foil!
That indoor stuff spells...tough. Dust off the snow and fill up the propane tank. Marinate well, cook it hot quickly on skewers.
Since you aren’t on a grill, seasoning becomes a little more important, since you won’t have that good grilled taste.
The steaks being so thin, they will be very easy to screw up, so be careful. You can go from tender/tasty/juicy to beef jerky within a minute if you aren’t on top of the situation.
I would recommend setting up as many pans as you can on however many large stove eyes you got. Put a thin layer of oil in each pan, and turn up to med/high heat. Season the steaks up GOOD. When all of the pans are HOT, throw as many steaks as you can on each pan.
Watch them carefully, because you are wanting to sear in the flavor on high heat, but you don’t want to burn them.
After you get them in the pan, let them cook on one side for about 6-7 minutes, and turn them. Cook on the other side for about 4-5min, and turn again. Cook for another minute or two, and remove it. They will finish cooking themselves after you remove them from the heat.
Since they are so thin, you won’t have to worry much about undercooking them. if you can get 4 stove eyes going, you should be able to do it in 2 rounds, assuming 4 steaks per pan.
Bottom line... When you go to do it, make sure you have the time dedicated to doing that one thing only. Don’t get sidetracked or distracted even for a few seconds. If the phone rings, let it go to voice mail. If the doorbell rings, they can wait outside... You get the idea. Too bad you aren’t on a grill for this, because it would be SO much easier. lol