In a medium saucepan, melt the butter over medium heat. Add the onion and cook, stirring, until softened, about 5 minutes. Stir in the cream and salt and pepper to taste.
To prepare a truffle cream sauce recipe, first you need to prepare your ingredients. First, you will need the following ingredients: 1 cup of heavy cream, 1 tablespoon of butter, 2 tablespoons of salt, and 1 teaspoon of pepper to taste. You will also need 2 tbsp. of kosher salt.