Prep the vegetables. Slice the cucumbers lengthwise, then into thin half-moons.
Thinly slice the red onion. Core the bell peppers and cut into thin strips or bite-size pieces. Halve the cherry tomatoes if using.
Soften the onion bite (optional but helpful). If raw onion feels too sharp, soak the slices in cold water with a pinch of salt for 10 minutes, then drain and pat dry.
This keeps flavor while toning down the sting.
Chop the herbs. Roughly chop parsley and any add-ins like dill or cilantro. Aim for about 1/3 cup loosely packed mixed herbs. Keep a little extra for garnish.
Make the dressing. In a small bowl, whisk together olive oil, the juice of one lemon (about 2 to 3 tablespoons), red wine vinegar, Dijon, grated garlic, honey, 1/2 teaspoon salt, and several grinds of black pepper.
Taste and adjust: more lemon for brightness, more honey for balance, more salt if it tastes flat.
Toss the salad. Add cucumbers, onion, bell peppers, and tomatoes to a large bowl. Pour in the dressing and toss gently until everything is well coated. Fold in most of the herbs.
Let it mingle. Let the salad sit for 5 to 10 minutes so the flavors come together.
This short rest makes a big difference, especially with cucumbers.
Finish and serve. Taste again. Add a pinch of salt, extra pepper, or a squeeze more lemon if needed. Top with remaining herbs.
Crumble feta over the top if you like, and sprinkle with red pepper flakes for a touch of heat.