Mashed Cauliflower and Carrots

1 (16 ounce) package frozen cauliflower

1 (16 ounce) package frozen carrots

1 (8 ounce) container fat-free sour cream

¼ cup apple cider vinegar

1 teaspoon garlic powder

salt and ground black pepper to taste

¼ cup butter

Place cauliflower and carrots in a large pot of lightly salted water; bring to a boil until vegetables are soft, 10 to 15 minutes. Drain and transfer vegetables to a large bowl.

Mash sour cream, vinegar, garlic powder, salt, black pepper, and butter into cauliflower and carrots by hand or using a food processor, until desired consistency.