A mandoline will come in handy for slicing the fennel and celery.

Remove the stalk and fronds from the fennel.

Slice the bulb very thinly using the mandoline.

Transfer to a large bowl.

Slice the celery and chop the shallot, then add them to the fennel.

In a small bowl, pour the oil and vinegar.

Season with salt and pepper to taste, then whisk with a fork to emulsify the vinaigrette.

Pour the vinaigrette over the vegetables and mix everything well.

Check the seasoning, add the walnuts and sprouts.

Add the shredded beef and mix everything together.