There’s a particular kind of opening night that tells you something real about a restaurant — not the speeches or the celebrity guests, but whether the room has any genuine warmth to it. L’Osteria’s debut at Elektrownia Powiśle, which took place on 28 May, had it. By the time Italian-Polish singer Armando Quattrone took to the mic and the pizza started arriving at tables, the place felt less like a launch event and more like somewhere that had already been open for years.