I've opened more than 25 restaurants. If I could start over, I'd make 1 major change to the menu. This as-told-to essay is based on a conversation with Andrew Schnipper, cofounder of multiple restaurants, including Schnipper's and Hamburger America. The conversation has been edited for length and clarity. When my brother and I opened Schnipper's in 2009, we thought having a broad menu made sense. We were focused on burgers, but we also served salads, sandwiches, and other comfort food. At the time, we thought people would want variety because, honestly, even we were asking ourselves how many burgers someone could eat every week. What I've learned over the years is that today's customers are looking for specialists. They want restaurants that do a few things really well. That's one of the biggest reasons our newer concept, Hamburger America, has such a focused menu. If you look at Hamburger America, there are a couple of burgers , a couple of sandwiches, and that's pretty much it.…