Preheat oven to 375°F.
In a large food storage bag, combine wine, stock, vinegar, Worcestershire, garlic and Dijon mustard. Season the meat with salt and pepper, and add to marinade. Refrigerate the steaks for 4 hours.
Soak potatoes in salted water in large bowl for a few minutes. Drain and pat dry.
Toss potatoes with about 3 tablespoons olive oil and season with thyme, salt and lots of peppercorn blend. Place potatoes on a baking sheet and bake 20 minutes then remove and cool to room temp.
Heat a cast-iron or oven-safe skillet over medium high heat.