Season the beef on both sides with salt and pepper. Place in a mixing bowl or baking dish and toss with ½ cup This Little Goat went to Hong Kong sauce until well coated. Let marinate for at least 30 minutes, or refrigerated up to overnight. \nPreheat the oven to 250 degrees.\nRemove meat from the marinade and transfer to a roasting pan or baking dish. Place in the oven and roast for about 1 ½ - 2 hours, until a thermometer reads 120-125 degrees. Let rest for at least 15 minutes before slicing.\nMeanwhile, while your meat rests, make your Hong Kong cream sauce by whisking together the sour cream, mayonnaise, Hong Kong sauce and lemon juice. Season to taste with salt and pepper and set aside for serving. \nRemove the string and slice the beef tenderloin into 1-inch thick slices. Transfer to a serving plater and top with freshly-torn parsley leaves. Serve warm or at room temperature, alongside Hong Kong cream sauce for dipping.