Curried Red Lentil and Swiss Chard Stew with Garbanzo Beans

INGREDIENTS

• 2 tablespoons olive oil
• 5 teaspoons curry powder
• 1 large bunch or 2 small bunches Swiss chard, tough stalks removed, coarsely chopped (about 12 cups)
• 1 15-ounce can garbanzo beans (chickpeas), drained
• 1 pound red lentils (about 2 1/4 cups)
• 3 14-ounce cans vegetable broth
• 1/4 teaspoon cayenne pepper
• 1 large onion, thinly sliced
• Plain yogurt