There's surely more story here, but we don't have it yet; this comes from an initial tweet by Penny Pollack of Dish, with additional details at Eater. Kendal Duque, the Everest vet and opening chef of Sepia who has been at Chicago Firehouse in the South Loop for several years and opened Mainstay Hospitality's new, Revolutionary War-era tavern City Tavern, is suddenly out at both places. His replacement at City Tavern— announced at the same time— is Jackie Shen, formerly of Red Light and Jackie's. There's no replacement yet at Chicago Firehouse, but John Caputo— longtime chef of Bin 36— has joined Mainstay as a partner and is covering Chicago Firehouse for now while working on a new place with Mainstay owner Matthew O'Malley.
You can't tell the players without a scorecard, and here's what we see on the field. Duque got respectable opening reviews at City Tavern, if not glowing ones (most seemed to think dessert was the star), but the concept came from owner Matthew O'Malley, and when we interviewed him some months back, the way he talked about the classic American food did seem more dutiful than personally inspired.
Shen has gotten a reputation lately for bouncing through short-term gigs for which she wasn't necessarily terribly well suited (Argent, Friendship Chinese) but it's worth recalling that she was at Red Light for most of a decade, and even Chicago Cut Steakhouse held her for a year or so. Offhand, City Tavern's classic American food seems more like that than anything else, but who can say whether this is the situation that will hold her after a peripatetic last several months.
And Caputo? This too is big news: Caputo has guided Bin 36 since 2001 and recently overhauled the menu (quite successfully in our opinion) to feature more small plates and charcuterie and cheeses; if not one of the very top restaurants downtown, perhaps, it's long been a perfectly reliable and respectable spot for business dinners and the like. So for him to leave as partner and executive chef and to join up with Mainstay suggests that something big and interesting must be down the road, but we'll just have to wait to see what it is. The Bin 36 site indicates that William Hewitt is Bin 36's current executive chef, but says that's been the case since spring, even though Google shows us Caputo being listed as executive chef at events (such as a Green City cooking demo) as recently as August.