I'm looking for a particular burger. The most important thing is that the restaurant grinds their own, and is willing to cook it medium-rare or even rare. It would be nice if it is a single patty that's about 8 ounces. Grass-fed would be a bonus.
I've tried a few places in Des Moines, and the best result was at Americana. The meat was overcooked at Centro. It was very overcooked at Gateway Market. I didn't ask for medium-rare at Zombie burger, and I thought the patties were too thin.