Place the beef in the freezer or refrigerator for a short time. You want it cold so you can cut it into the smallest pieces possible. Sharpen your knife well before using it. First, slice the beef into thin strips, then cut across the strips to make small cubes.

Finely chop the celery leaves and parsley leaves.

Use a ring mold to shape the beef mixture on a plate, making a small well in the center to add the egg yolk.

Top with the chopped herbs and capers, plus a little extra salt and pepper. Remove the ring mold, mix the steak tartare with the egg yolk, and spread on buttered slices of bread.