Gotta love Rob Wasserman's sense of humor. For today's reopening of 500º (1504 Sansom St.), he has named the burger of the week the "The Spontaneous Combustion," the cause of the fire that closed the place for two weeks. Crafted by Matt Levin, the burger has homemade hot sauce, pepper jack and smoked mayo.

Paesano's, the sandwicheries in Northern Liberties and Italian Market, will begin offering gluten-free bread, starting next week. Owner Peter McAndrews tells me that his kids have celiac disease. The bread he'll use is expensive, so he'll have to charge $1 extra. His South Philly shop has gone to seven-day operation.

And in non-sandwich news: Stephen Starr has won the catering contract at the Philadelphia Museum of Art, replacing Restaurant Associates after 16 years.