Spicy Black Bean Soup

INGREDIENTS

• 2 tablespoons olive oil
• 2 medium yellow onions, chopped
• 3 celery ribs, chopped fine
• 1 large carrot, peeled and sliced into thin rounds
• 6 garlic cloves, pressed or minced
• 4½ teaspoons ground cumin
• ½ teaspoon red pepper flakes (use ¼ teaspoon if you're sensitive to spice)
• 4 (15-ounce) cans of black beans, rinsed and drained
• 4 cups low-sodium vegetable broth
• ¼ cup chopped fresh cilantro (optional)
• 1 to 2 teaspoons sherry vinegar, to taste, or 2 tablespoons fresh lime juice
• Sea salt and freshly ground black pepper, to taste
• Optional garnishes: diced avocado, extra cilantro, thinly sliced radishes, tortilla chips...