Put the filet mignon into the freezer for about an hours before mincing, so it slices more easily. By hand or in a food processor, mince the filet mignon with a few pulses.
In a bowl, add all the liquid ingredients and whisk until combined. If you are adding in your egg yolk here and not on top of the finished tartare, this is the time to add it, along with the liquid ingredients. If adding in on top, see the final step.
Then, add the minced ingredients and whisk together.
Finally, add the meat into the mix and combine with a spoon, making sure to coat the meat with the dressing completely. Salt and pepper to season; do not over salt.
If serving with egg yolk on top of tartare, pack each meat mixture into 2.5 - 3.5 inch metal ring. Gingerly place the whole egg yolk on top of each tartare. Release ring to set meat on plate. Enjoy with crispy baked crostini, or french bread drizzled with salt and olive oil.
