To begin place your red onion, white vinegar, lemon juice and sea salt in a bowl and mix together throughly to help break down your red onion. This will pickle them slightly and take away that raw onion heat and also acts as the beginning of your dressing.
Begin chopping your cucumber and tomatoes and place into large salad bowl.
Add in your olives.
To finish your onion dressing add in your garlic, black pepper, dill leaves and olive oil. Bring together your dressing and pour over your salad bowl, tossing it through your cucumber mix.
To finish your salad add your block of feta on top of the salad and finish with a dusting of your dried oregano. Enjoy it all together.