The skillet used to cook the pork should have some cooking liquid in it. Place this skillet over medium heat. Pour the reduced sauce into skillet and stir to combine. Stir in apricot preserves and heat sauce to boiling. Boil 5 minutes, stirring occasionally, until slightly thickened. Remove skillet from heat. Beat in butter, 1 piece at a time, with wire whisk, adding the next piece only after the first has been completely beaten in and melted. When all of the butter has been beaten in, taste sauce and season with salt and pepper if desired. Remove and discard bay leaves and thyme sprig.