Sprinkle beef fillets evenly with salt and pepper.
Melt butter and olive oil in a large nonstick skillet over medium-high heat.
Add fillets, and cook 6 minutes on each side or to desired degree of doneness.
Remove fillets from skillet, and keep warm.
Add wine, broth, and peppercorns to skillet; cook 20 minutes or until liquid is reduced by half.
Stir in evaporated milk and mustard; cook over low heat 5 to 7 minutes or until slightly thickened.
Return fillets to skillet, and serve warm.
Garnish, if desired.