olive oil • yellow onion, finely chopped • garlic, finely chopped • kosher salt • tomato paste • vodka • red pepper flakes • cans white beans (cannellini, Great Northern or garbanzos), drained but not rinsed • kale, ribs removed, leaves torn or coarsely chopped (or any dark, leafy green - Swiss Chard, broccoli rabe) • heavy cream • Grated Parmesan,