Reduced-Fat Funeral Potatoes | America's Test Kitchen

Ingredients

• 3 ounces (2 cups) reduced-fat potato chips
• 1 1/2 tablespoons ranch-flavor salad dressing mix
• 1 1/2 cups 2 percent low-fat milk
• 1 tablespoon cornstarch
• 2 teaspoons olive oil
• 2 onions , chopped fine
• 3 garlic cloves , minced
• 1 3/4 teaspoons salt
• 1/2 teaspoon dry mustard
• 1/2 teaspoon dried thyme
• 1/4 teaspoon pepper
• 1 (12-ounce) can evaporated milk
• 30 ounces (8 cups) frozen shredded hash brown potatoes
• 4 ounces extra-sharp cheddar cheese , shredded (1 cup)
• 1/2 cup low-fat sour cream
• 1/4 cup grated Parmesan cheese