Lobster mac 'n' cheese is hardly the novelty it once was, but in the expert hands of the Pubbelly Group (PB Steak, Pubbelly, Pubbelly Sushi, L'echon, and Barceloneta), it's elevated to new heights. At PB Steak in Sunset Harbour, chef-partner Jose Mendin and chef de cuisine Guillermo Concho rely on a béchamel sauce spiked with blue crab and white cheddar to give their lobster mac 'n' cheese ($19) an assertive edge. The kitchen frequently switches up the ingredients used in this all-American side dish, and predecessors have included a cheddar and bacon version, roasted apple and chorizo, and even mac 'n' cheese escargots. Given that they've all been stellar, there's no reason to fear change. Besides, popular dishes like the steak tartare sliders ($5 each) and braised beef short ribs ($25) aren't going anywhere. With PB Steak, Mendin and partners Andreas Schreiner and Sergio Navarro — AKA the Pubbelly boys — have given Miami something it was missing: an innovative and casual steak house with high-quality fare at reasonable prices.