2 tablespoons extra-virgin olive oil
1/2 large onion, thinly sliced
2 garlic cloves, minced
1/2 jalapeño, seeded and sliced
1/2-1 pound braising greens (chard, mustard greens, kale or young collards)
Salt and freshly ground pepper
1/2 pint cherry tomatoes, halved
2 tablespoons water
2 teaspoons white wine vinegar
Serves 1-2