This subterranean dining room is unique in its location, manner and mission. Tucked underneath Roister, it's a sultry and chic reprieve, as guests hand over all decision-making to the team. Celebrating the once popular mid-western "supper club" vibe, St. Clair—also Alinea Group Grant Achatz's birthplace—is furnished with low ceilings, leather banquettes and comfy green chairs.Solo diners head to the bar for a stiff cocktail and slab of prime rib, while larger parties start their meal with smaller bites, like crab cakes and oysters Rockefeller. Prime rib may be the central focus, but sides like "Yorkshire pudding" popovers and caramelized mushrooms with beef balsamic vinegar reduction are comfort to the core. Grasshopper pie completes the classic American feast.