Seasoned beef patties, caramelized onions and two cheeses on rye spread with a homemade burger sauce, griddled in butter until crisp.
For a crisper crust, spread the outside of the bread with mayonnaise instead of cooking it in butter. A dash of hot sauce in the sauce adds a little kick.
Find it online: https://www.receipster.com/ultimate-patty-melt-secret-sauce-4/