Hungarian Mixed Bean Goulash

Name: Hungarian Mixed Bean Goulash
Ingredients: 2 teaspoons vegetable oil; 2 large onions, thinly sliced; 1 large green bell pepper, thinly sliced; 2 cups vegetable broth; 1 (6 ounce) can tomato paste; 1 (16 ounce) can kidney beans, rinsed and drained; 1 (16 ounce) can white beans, rinsed and drained (cannellini or Great Northern beans); 1 (16 ounce) can lima beans, rinsed and drained; 2 medium potatoes, unpeeled, cut into 1/2 inch cubes; 2 tablespoons paprika; 1 teaspoon dried basil; 1⁄2 teaspoon caraway seed; 1⁄4 teaspoon pepper; 1 cup plain yogurt