SERVES 2 TO 4
1 pound freshly ground beef (store-bought or home-
ground)
4 soft hamburger buns, preferably Martin’s Potato
Sandwich Rolls
2 tablespoons unsalted butter, melted
Vegetable oil
Kosher salt and freshly ground black pepper
1 small onion, finely sliced (optional)
4 deli-cut slices American cheese