Spicy Kale, White Bean and Orzo Soup

Bahan-bahan (6 porsi)

• 1 tablespoon olive oil
• 1 medium white onion, peeled and diced
• 1 stalk of celery, thinly sliced
• 4 cloves garlic, minced
• 1 teaspoon crushed red pepper flakes
• 8 cups vegetable stock (or chicken stock)
• 2 (15-ounce) cans white beans, rinsed and drained
• 2 bay leaves
• 2 large sprig fresh rosemary
• 1 cup uncooked orzo
• 1 small bunch of fresh kale, roughly chopped (with tough stalks discarded)
• juice of 1 lemon
• fine sea salt and freshly-cracked black pepper
• freshly-grated Parmesan cheese, for topping (optional)