In a small bowl or measuring cup, whisk together the fresh lemon juice and kosher salt until the salt dissolves. Drizzle in the extra-virgin olive oil while whisking continuously to emulsify the dressing.

Place the diced roasted or canned beets in a large mixing bowl. Pour half of the lemon vinaigrette over the beets, tossing gently to coat. Let marinate for a few minutes.

Seed and halve the cucumber, then slice it thinly.

Crumble the feta cheese into bite-sized pieces.

Add the sliced cucumber and crumbled feta to the bowl of marinated beets. Sprinkle in the chopped dill and pour in the remaining vinaigrette. Gently toss to combine.