Black Bean Soup | America's Test Kitchen

Ingredients

• 1 pound dried black beans (2 1/2 cups), rinsed and picked over
• 4 ounces ham steak , trimmed of rind
• 2 bay leaves
• 5 cups water
• 1/8 teaspoon baking soda
• 1 teaspoon table salt
• 3 tablespoons olive oil
• 2 large onions , chopped fine (about 3 cups)
• 1 large carrot , chopped fine (about 1/2 cup)
• 3 ribs celery , chopped fine (about 1 cup)
• 1/2 teaspoon table salt
• 5 - 6 medium cloves garlic , minced or pressed through garlic press (about 1 1/2 tablespoons)
• 1/2 teaspoon red pepper flakes
• 1 1/2 tablespoons ground cumin
• 6 cups low-sodium chicken broth
• 2 tablespoons cornstarch
• 2 tablespoon water
• 2 tablespoons lime juice , from 1 to 2 limes
• Lime wedge
• Minced fresh cilantro
• Red onion , finely diced
• Avocado , diced medium
• Sour cream