Three bean soup

Three bean salads are usually the stuff of picnics and potlucks. But that same combination of canned beans and fresh green beans turns soft and silky when simmered into broth, rounded out with tomato paste for body and sweetness, ground coriander for a warm note and a sprinkling of Parmesan for depth. And just as in a classic three bean salad, a garnish of lightly pickled red onions adds acidity and crunch.