Season tenderloins with salt and pepper.
Heat oil in a skillet and sear tenderloins. Remove pork from skillet and discard excess fat.
Add onion, carrot and 1 portion of butter and cook until tender. Return tenderloins to skillet and stir in flour. Add wine and cook, uncovered, for 30 minutes.
Remove tenderloins from skillet, add the beef stock and reduce for 20 minutes. Strain reduced sauce and return to skillet. Cook at medium heat and add prunes to sauce and pork tenderloins. Stir in heavy cream and bring to a boil. Correct seasoning. Add remaining butter and stir.
To serve, cut pork in slices and place in a serving platter. Pour wine and prune sauce over.
Serve with potato puree or with vegetables.