A patty melt is a type of hamburger sanwich consisting of a hamburger (or other ground meat) patty, pieces of sautéed or grilled onion, and cheese between two slices of bread (traditionally rye, though sourdough, or Texas toast have recently been substituted). The sandwich is then grilled so that the cheese melts thoroughly. At some places it may include salad dressing. A popular Northwestern variant, made popular initially at "Lucy's Place" is made with a sliced salmon fillet with a melted slice of dill havarti on a hard sourdough roll.