In a small bowl, whisk together fresh lemon juice and kosher salt until dissolved. Gradually drizzle in olive oil, whisking until emulsified.

In a large bowl, toss diced beets with half of the vinaigrette and let marinate for at least 15 minutes.

Before serving, add cucumber, feta, and dill to the marinated beets, then pour in remaining vinaigrette.

Gently toss the salad ingredients together using a large spoon to mix while keeping feta chunks intact.