Prepare the dressing by adding the yogurt, garlic, lemon, dill, honey, vinegar and red chili pepper flakes in a medium size bowl. Whisk to incorporate.
Slice one end off the cucumber and using a mandolin on the second thinnest setting, slice. You want to start the slicing on the end that was cut off. Take care when getting toward the end and use the guard if the mandolin comes with one.
Using the mandolin, carefully slice the onion and pepper on the thinnest setting. Place the cucumber, onion, and peppers in the bowl with the dressing and stir.
Add salt and pepper to taste.
English cucumbers are the idea cucumber to use because they are seedless and dense.