Cauliflower Leek Soup

Bahan-bahan (6 porsi)

• 2 large leeks, (white and light green parts only)
• 2 tablespoons olive oil
• 1 head (about 2 pounds) cauliflower
• 3 medium garlic cloves, (minced)
• 4 cups vegetable broth
• ½ cup half and half ((or milk))
• salt and pepper, (to taste)
• fresh thyme or grated cheddar cheese, (for serving if desired)