Combine the egg, basil, pine nuts, shallots, garlic, salt, and pepper in a food processor or blender and purée. Slowly stream in the oil and continue to process until the mixture becomes thoroughly emulsified. Add the Parmesan and process for 15 seconds.
Heat the cream in a small saucepan over high heat, add the mixture from the food processor or blender, and cook, whisking constantly, for 2 minutes. Remove from the heat. Serve immediately.
Yield: 1 1/3 cups