Cooking short-order hamburgers -- need advice

I am trying to make "little hamburgers" the way they make them at the short-order place (Greene's Hamburgers) that I grew up with in Detroit. I rarely see them made this way, but it's my favorite and seems simple -- yet, I have a small problem.

The way they make them is, they take a small, pre-made ball (I use 2 oz.) of hamburger, smoosh it down on the grill with a spatula, drop a large mound of shredded (not diced) onions on top and smoosh those into the patty. They let the patty grill for a bit, then flip it over and put the bottom of a bun on top and the top of the bun on top of that. When the second side is cooked, they lift the patty with a spatula, put the top of the bun underneath, pull the spatula out, turn the hamburger right-side-up and voila! I remember the whole process taking maybe 2-3 minutes.

My problem is, when I flip the patty over so the second side can cook, I keep burning the onions. Of course, I can use a lower cooking temperature, but then the burgers take longer to cook. I guess there is some perfect temperature for cooking the burgers quickly without burning the onions? Any short-order cooks -- professional or amateur -- out there who can tell me the secret? Thanks!

Hmm

I personally like them a bit crispy and blackened, tastes great...

Also, the related place that Holly Moore reviewed shows that some of the onions have been blackened/burnet, and it looks great



...so maybe your results are what is to be expected?

How about if you put a lid over the burger it would cook a bit faster.

Do you think the shredded onions could have been mixed with some cooking oil or grease before being added to the patty? That would help the burn factor.

Try cooking it longer on the first side. It should be possible to cook it mostly through without burning the first side because the burger is small and thin. Experiment by varying this cooking time ratio until you achieve burger/onion perfection.

Thanks, everyone. You have helped me to solve the problem. The "trick" is to use a cast iron pan, set the temperature (I have a gas stove) LOW and let give the pan a minute or two to heat up before putting the burger on. The cast iron, apparently, is a very good heat absorber and radiator, so a low flame is all you need.