You should be able to get a reasonable steak stovetop using a cast iron grill pan, if you have a strong enough exhaust. Oil the cast iron pan (with canola or such), then heat it very hot, until it starts to smoke. Make sure the meat is completely dry on the outside (wipe with a paper towel, water will prevent browning) and gently place in the pan. Leave it there for a minute or two (it'll smoke quite a bit!), rotate 90° to get the nice grill marks. Leave for another minute or two. Flip, and repeat for the other side.
It may splatter, have a splatter screen handy. It will smoke, quite a bit, make sure the exhaust is on high.
You will probably have a medium-rare steak now. Using a thinner cut will make it more well done (you can cut a thick steak in half with your chef's knife, making two thin steaks); so will plopping it in the oven (not sure if you want the oven before or after searing, I like 'em medium rare...).
Remember to let the meat rest for 5 minutes or so before serving.
Also, if your steaks are coming out ridiculously tough, you're probably using the wrong cut of meat, or some terrible grade. What cut are you using?
[edit: I should note that, in case it wasn't obvious, the burner should be up pretty high]
Edit by rumtscho There is a reason this answer specifies a cast iron pan. If you are limited in your cookware choice, pay attention to the maximum temperature your pan can tolerate. If you are using a non-stick pan, you have to go on medium heat and wait longer, else you'll damage the pan. (And sorry, but you can't get it as tasty as on high heat that way).
I would actually recommend the opposite of what was said above. Since the meat is so thin you may have much better results pan searing it in an extremely hot pan from slightly frozen. This way the outermost layer will start to undergo the maillard reaction long before the inside of the steak reaches a medium-rare temp and will give you a better chance of preventing it from overcooking.
This link provides an overview of the process for a much larger piece of meat then your using but the searing process is what your concerned most with since your steaks are so thin. You will likely have to play with the timing a little bit with regards to how frozen the steak needs to start out but I figure erring on the side of too frozen is best since you can then heat them in the oven to the internal temp your looking for.
http://www.thekitchn.com/for-the-perfect-steak-first-freeze-it-solid-then-cook-for-an-hour-165793
Best Answer
I think this question is hard to answer exactly. The easiest way to estimate the duration of the steak in the oven is to cook the steak at ~260°C and after >3 minutes each side (altogether >6 minutes) to measure the inner temperature of the steak. 57-60°C should be medium rare. Of course this his method requires a thermometer. (source: here and here)