2015 saw the closure of Donatella Arpaia’s Prova in Chelsea, but this Prova Pizzabar is more popular for its counter selling pizza by the slice, far quicker than getting a Shake Shack burger a few yards away. The dining space is small, but insulated from the bustle of the Grand Central; there is also a bar space which works well in the small setting. The classic eggplant Parmesan is excellent – hearty and belly-warning; however, the Tartufata with truffle cream, Porcini Mushrooms, Mozzarella and Speck ($8 slice, $42 pie) might be NYC’s best white pie after Juliana’s No.1, but such a different beast: a bready crust with real bite. This is apparently Detroit-style, and it pulls off slices but definitely not for that price. A small selection of wine and beers is available and service is below-average but the atmosphere is a little better than you’d expect from a restaurant – other than the Oyster bar – in a terminus station.