Slice celery stalks on a bias into 1/4-inch thick pieces and remove any tough strings.

Mince the shallot, pit and slice the dates, crumble the feta cheese, and chop the mint.

In a dry skillet, toast walnuts over medium heat for 2–4 minutes until golden brown.

In a bowl, whisk together lemon juice, white wine vinegar, and shallot. Add olive oil gradually, whisking to emulsify.

Combine celery, walnuts, dates, feta, and mint in a bowl. Drizzle with dressing and toss gently to combine.

Serve immediately for the freshest flavors, or let sit for up to 30 minutes before serving.