Onions, pickles, tomato… Not long ago, these items and a few more were the only garnishes people dared to place atop their ground beef patties. But of late, hamburger makers have been pushing the envelope on this all-American, meat and cheese sandwich. Rare, high-end ingredients—previously reserved for the porcelain plates at Michelin-rated restaurants—are now commonly wedged between artisan buns. Culinary creators deploy quail eggs, bone marrow, truffle oil and foie gras to spruce up this humble, backyard-barbeque staple. The possibilities are seemingly endless. In honor of the grilling season, we’ve compiled a list of local joints serving some of the region’s most unique burgers.