The Most Talked-About Sandwich in Dallas: A Patty Melt From a Low-Key Deep Ellum Bar. 1. GRILLED PATTY PAN SQUASH: Cut squash length wise and remove seeds. squash is. 2. SMALL PATTY PAN SQUASH: Wash squash. Place in large saucepan. continue. As great dinner sandwiches go, it is hard to beat patty melts: ground beef, Swiss cheese and caramelized onions griddled on rye bread until they become crisp, oozing.