There’s a brick building nestled in the Laurel Highlands of Pennsylvania where magic happens daily – not the rabbit-out-of-a-hat kind, but the “oh-my-goodness-this-is-so-good-I-might-cry” variety.

In the heart of Louisville’s Highlands neighborhood sits a time capsule disguised as a diner. Twig and Leaf stands proudly at the corner of Bardstown Road and Douglass Boulevard, its neon sign glowing ...