Place sliced kale in a large mixing bowl and sprinkle with salt.
Massage the kale with your hands for 2 to 3 minutes until leaves are softened and reduced in volume.
In a small jar or bowl, whisk together olive oil, lemon juice, minced garlic, oregano, and black pepper.
Add cherry tomatoes, cucumber, red onion, and Kalamata olives to the bowl with the kale.
Pour the dressing over the vegetables and toss thoroughly to ensure even coating.
Top with crumbled feta cheese and serve immediately or let rest for 15 minutes to allow flavors to meld.