Bring A Large Pot Of Lightly Salted Water To A Boil. Add Pasta And Cook For 8 To 10 Minutes Or Until Al Dente; Drain. Melt Butter In A Large Heavy Skillet Over Medium Heat. Saute Onion And Bell Pepper Until Soft, About 5 Minutes. Add Ground Pork, And Cook Until Evenly Brown. Drain Excess Fat. In A Large Pot, Heat Spaghetti Sauce Until Bubbling. Stir In Pork Mixture, Pasta And Sour Cream. Cook Until Heated Through, About 5 Minutes.