Cucumber tomato mix: Dice one half of the cucumber and add to a large bowl, along with the tomatoes, red onion, olive oil, 2 tablespoons lemon juice, garlic powder, and half of the oregano. Season with salt and black pepper, to taste, and stir to combine. Cover and set aside until ready to use.
Tzatziki sauce: shred remaining cucumber with a box grater and place in another large bowl. Add Greek yogurt, minced garlic, dill, and the remaining oregano and lemon juice. Season with salt and black pepper, to taste, and stir to combine. Cover and set aside until ready to use.
Spread the hummus into a uniform layer on small serving platter (or in an 8” x 8” casserole dish), then top with the Tzatziki sauce.
Use a slotted spoon or strainer to drain excess liquid from the seasoned tomato, red onion, and cucumber mixture before spreading on top of the Tzatziki sauce.
Add the Kalamata olives, followed by the crumbled Feta and fresh chopped parsley. Serve with vegetable sliced veggies, chips, or pita for dipping. Enjoy!