Ingredients

2 tablespoons olive oil

1 cup chopped onion

1 cup chopped fennel bulb

1 1/2 teaspoons fennel seeds

2 large (2 1/2- to 3-inch-diameter) beets, peeled, cut into 1/2-inch cubes

2 cups low-salt broth

1 cup unflavored plain or greek yogurt

Fennel fronds (for garnish)