Slice and salt the cucumbers: Thinly slice the cucumbers and place them in a colander. Sprinkle with the sea salt and toss. Let sit for 10–15 minutes to draw out excess moisture, then pat dry with paper towels.
This keeps the salad from getting watery.
Make the dressing: In a large bowl, whisk the yogurt (or sour cream), mayonnaise, lemon juice, lemon zest, olive oil, garlic, Dijon, and honey until smooth.
Add the cheese: Fold in the feta crumbles. You want some small pieces for texture. Season with black pepper and a pinch of red pepper flakes if using.
Stir in the dill: Add the chopped dill and mix gently.
Taste the dressing and adjust acidity or sweetness as needed.
Combine: Add the salted, dried cucumber slices to the bowl. Toss gently until everything is evenly coated.
Finish and serve: Transfer to a serving dish. Sprinkle with extra dill and a little flaky salt.
Serve right away for maximum crunch, or chill for 15–20 minutes to meld flavors.