In a large bowl, whisk together the Greek yogurt (1/3 cup), extra-virgin olive oil (2 tablespoons), apple cider vinegar (1 tablespoon), chopped fresh dill (2 tablespoons), kosher salt (1/2 teaspoon), black pepper (1/4 teaspoon), and honey (1 teaspoon).
Add sliced English cucumbers (2) and thinly sliced red onion (1/4 cup) to the bowl. Toss together to coat.
Serve immediately (see notes on making ahead).
If prepping ahead of time, mix the dressing and store in a separate container from the sliced cucumbers and onions. Just before serving, toss everything together. Otherwise, the cucumbers will get mushy and the dressing quite watery if it sits too long already dressed.
If using regular cucumbers instead of English, I recommend slicing lengthwise and scooping out the seeds and peeling them (fully or partially). This will help decrease the water content of the cucumbers and also help take away some of the bitter flavor and tougher texture of the peel.
Ingredient substitutions: lemon juice may be used instead of apple cider vinegar, sugar or agave used instead of honey, sour cream instead of Greek yogurt. Onions may be omitted or substituted with green onions for a more mild taste.