America’s Test Kitchen took a look at how to recreate the Jucy Lucy at home back in 2007:
Minneapolis taverns are famous for serving a sandwich called the Jucy Lucy, a moist beef burger stuffed with American cheese. Replicating the Jucy Lucy recipe seemed easy enough—simply seal a slice of American cheese between two beef patties and throw it on the grill. But our burgers, cooked to well-done to melt the cheese inside, were dry and tough. Or worse, the cheese melted through the meat, leaving an empty cavern where the cheese had been. We wanted to figure out how to keep the Lucy juicy and hold the cheese inside.
Here’s a link to their winning recipe and a video demonstrating their work.