Human: How do you make a good sour cream sauce for potatoes? Assistant: 
To make a good sour cream sauce for potatoes, start by combining 1 cup of heavy whipping cream with 2 tablespoons of white vinegar. Then add 1/4 teaspoon of salt and 1/8 teaspoon of freshly ground black pepper to the mixture. Heat the mixture over medium heat until it begins to bubble, then reduce the heat to low and simmer for 5 minutes. Finally, stir in 1/2 cup of sour cream and serve warm.