Stovetop Mac and Cheese

Bahan-bahan (4 porsi)

• 1 pound uncooked pasta (I used cavatappi*)
• 3 cups water
• 2 cups milk
• 1 teaspoon Dijon mustard
• 1 teaspoon fine sea salt
• 1 teaspoon garlic powder
• 2 to 4 cups (8 to 16 ounces) freshly-grated sharp cheddar cheese (see note below)
• 1 cup (1 ounce) finely-grated Parmesan cheese
• freshly-ground black pepper, to taste