Prepare Tzatziki Sauce: In a bowl, combine Greek yogurt, grated cucumber, minced garlic, lemon juice, and fresh dill. Mix well, add salt and pepper to taste, then refrigerate to let the flavors meld.

Cook Beef Mixture: Heat olive oil in a skillet over medium heat. Sauté the chopped onion until it turns translucent, about 3-4 minutes. Add minced garlic and cook for another minute until fragrant.

Season and Brown Beef: Add ground beef to the skillet along with oregano, smoked paprika, cumin, salt, and black pepper. Cook, stirring occasionally, until the beef is fully browned and cooked through, about 8-10 minutes.

Assemble Bowls: Divide the cooked rice or quinoa among serving bowls. Top each bowl generously with the beef mixture, then arrange cherry tomatoes, red onion, olives, and feta cheese on top for a colorful display.

Add Tzatziki and Garnish: Spoon a generous dollop of tzatziki over each bowl. Finish with a sprinkle of fresh parsley or dill, and garnish with optional lemon wedges for a zesty touch.