2 whole garlic heads
1 tablespoon olive oil
3 tablespoons water
10 ounce whole-grain penne (such as Barilla)
2 3/4 cups 1% low-fat milk
3 1/2 tablespoons all-purpose flour
1 teaspoon kosher salt
1/2 teaspoon freshly ground black pepper
4 ounces sharp cheddar cheese, shredded and divided (about 1 cup)
2 ounces part-skim mozzarella cheese, shredded (about 1/2 cup)
Cooking spray