Serve with

1. Slice tenderloin into very thin pieces. Cut each piece into thin strips, and then cut into very small dice.
2. Once all tenderloin has been chopped, transfer to a bowl, cover with plastic wrap and refrigerate until ready to use.
3. Preheat oven to 450f. On a tray place marrow bones, cut side up. Roast for 15-20 minutes or until lightly brown and cooked. Remove from oven let cool.
4. Spoon out the bone marrow once cool and add into a bowl. Set aside the empty bones to later to fill with the tartare and serve from.
5. In a small bowl combine the egg yolk, anchovies, capers, cornichons, mustard, Worcestershire, bone marrow and mix well.
6. Remove diced beef tenderloin from refrigerator and combine with fold into egg yolk marrow mixture. Combine well.
7. Using the bone marrow bones to a plate and serve from carefully spoon the tartare mixture into the luge of the bone marrow to sit in. Garnish with chopped chives. Add kettle chips, crostini’s and serve!