One of the many joys of life in Manhattan is turning a corner—and finding something you hadn’t noticed before.  This restaurant, for example—how could Trestle on Tenth have been here on the corner of 24th and Tenth Avenue since the summer of 2006—and we’ve not yet frequented its twenty-seat garden with its cherry and locust trees?  This very afternoon then, we’ll make up for lost time—and sit beneath the trees, the sunlight dappling our table as we sip a frosty Stone I.P.A., from California.  The ambiance is local; the garden filled with low-maintenance swells drawn to the pastoral pleasures of this rustic brick-walled garden.  Chef and owner, Swiss-born Ralf Kuettel (formerly of Union Square Café and Zoë), offers food that is affordable and driven by memories of his Alpine background.  Furthermore, he has a fascination for the phrase “You are what you eat”—and for us, that means roasted jerusalem artichokes and roasted heirloom beets and gratinéed pizokel (imagine gnocchi invented by the Swiss), with caramelized onions and gruyère.   For dessert, there’s pineapple upside down cake, with pistachio ice cream—and coffee from La Colombe.  According to Kuettel, his goal is to enrich the neighborhood.  As for us, we’re sated and completely smitten—and ready to linger around until dinner.