Wash and peel the russet potatoes. Cut them into thick fries, approximately ½ inch wide. Soak the cut fries in cold water for at least 30 minutes to remove excess starch. Drain and pat dry.

In a deep fryer or large pot, heat vegetable oil to 350°F (175°C). Fry the potatoes in batches, without overcrowding, until golden brown and crispy, about 5-7 minutes. Remove and drain on paper towels. Season with salt while hot.

Season the filet mignon steaks generously with salt and black pepper on both sides. In a large skillet over medium-high heat, add olive oil. When the oil is shimmering, add the steaks. Sear the steaks for about 4-5 minutes on each side for medium-rare, adjusting time for desired doneness. In the last minute of cooking, add fresh thyme to the skillet and baste the steaks with the oil and thyme.

In the same skillet used for the steaks, reduce the heat to medium. Add butter and let it melt. Add crushed black peppercorns and sauté for about 30 seconds. Stir in the heavy cream, Dijon mustard, and Worcestershire sauce. Simmer for 3-5 minutes, stirring frequently, until the sauce thickens slightly. Season with salt to taste.

Plate the seared filet mignon alongside the hand-cut potato fries. Drizzle the velvety peppercorn sauce over the steaks and serve immediately. Enjoy your meal!