Break the cardinal rule of grilling -- don't press the patties! -- with this diner-style smash burger, made on the grill in a cast-iron griddle or skillet. The recipe comes from Weber's Ultimate Grilling, a new book by the grill company's resident chef, Jamie Purviance.
A griddle pan (or a large, short-handled skillet) makes a grill more multifunctional: Fry onions for brats or char peppers for fajitas. Plus, you can use it indoors over two burners. Lodge sells a nice reversible version for $55.