Easy Cheddar Cauliflower Soup

Bahan-bahan (6 porsi)

• 2 tablespoons butter (or olive oil)
• 1 medium onion (chopped)
• ¼ cup all-purpose flour
• ½ teaspoon salt
• 2 cups milk
• 1 cup water
• 3 cups chicken broth
• 1 head cauliflower (chopped into 1-inch chunks)
• 4 -5 teaspoon Dijon mustard (to taste)
• 1/8 to 1/4 teaspoon cayenne pepper (I promise this doesn't make it spicy. It just adds depth of flavor.)
• 2 cups sharp cheddar cheese (shredded, plus more to garnish)
• salt and pepper (to taste)
• green onions (or chives to garnish)