This simple pasta dish stars barely caramelized onions simmered in white wine, tangy pecorino Romano, black pepper and dried oregano for earthy, herbal contrast. It’s inspired by a Pugliese classic traditionally made with sweet Italian Tropea onions, a version of which chef Filippo Guarera prepared for us at his restaurant Osteria del Cardinale in Campagnano di Roma, about 30 minutes north of Rome. Cooking the onions until tender and just beginning to brown boosts their sweetness, providing a perfect counterpoint to the sharp, salty cheese. We added lemon zest to bring citrusy brightness to the sauce. After trying the dish with a handful of pasta types, we found that hearty whole-wheat noodles were our favorite; their nuttiness complements the onions, cheese and oregano. We preferred the short, chunky shape of penne, which gave the dish some heft; fusilli works, too, though we found that the spirals sometimes broke apart as they cooked in the sauce.