Cook the Ground Beef: Heat the olive oil in a large skillet over medium-high heat. Add the ground beef and cook, breaking it apart with a spoon, until browned and cooked through (about 6-8 minutes). Drain any excess fat if necessary.

Add the Onion and Garlic: Add the diced onion and minced garlic to the pan with the beef and sauté for about 2-3 minutes, until the onion becomes translucent and fragrant.

Add the Tomatoes and Olives: Stir in the halved cherry tomatoes and chopped Kalamata olives. Cook for another 3-4 minutes, allowing the tomatoes to soften and release their juices.

Season: Sprinkle in the dried oregano, basil, and cumin (if using). Season with salt and pepper to taste. Stir everything to combine and cook for an additional 2-3 minutes.

Add the Feta Cheese: Remove the skillet from heat and stir in the crumbled feta cheese, allowing it to melt slightly into the mixture.

Garnish and Serve: Garnish with fresh parsley or basil, if desired. Serve the Mediterranean ground beef stir fry as is or with a side of rice, quinoa, or a green salad.