Cut the cucumber into rounds that are a 1/2 cm thick (a little under a 1/4 inch), then add the slices into a colander with a bowl underneath and season with salt

In the meantime, add the Greek yogurt into a large bowl, along with the Dijon mustard, grated garlic, chopped chives, chopped dill, and lemon juice, then season with salt & pepper and whisk together, once it's well mixed, slowly add in the olive oil while whisking continuously

After leaving the salted slices of cucumber for 5 to 10 minutes, transfer them over some paper towels, all in a single layer, and pat completely dry, removing any excess salt if there is too much

Transfer the slices of cucumber into the bowl with the yogurt dressing, along with the diced red onion, diced red bell pepper, and corn, season with black pepper, and gently mix together until well mixed

Serve at room temperature or chilled, enjoy!