That tent going up today outside the giant airplane outside the Franklin Institute: Caterer and pioneering restaurateur Steve Poses (Frog/Commissary) is prepping for Saturday's soft-opening of Frog Burger, his take on the upscale burger stand.

It will be open periodically over the next two weeks before the grand opening during the week of June 14. Hours will be 11:30 a.m. to dusk daily. It's supposed to be open through the summer, with a shutdown date dictated by weather.

Here's the menu, which is a tad more ambitious than the norm: Fried green tomatoes. Grilled corn with chili-lime butter. "Chilled" gazpacho (um, opposed to the hot kind?).

Burger rundown -- "bibs available" -- includes turkey, beef, marinara, and a "Love Burger," between two grilled-cheese sandwiches and topped with special sauce. (Hmmm. I wrote awhile back that Stephen Starr trademarked the phrase "love burger.")

There's a hot dog. A crab roll. Shakes with Bassett's ice cream (and with carrot cake or chocolate cake mixed in). And beer, wine, and sangria.

The museum will offer discounted parking at $3 after 5 p.m. in its garage.