Heat olive oil in a large skillet over medium heat.

Add diced onion and sauté for about 3-4 minutes until softened.

Stir in minced garlic and cook for an additional minute until fragrant.

Add the ground beef to the skillet, breaking it apart with a spatula. Cook until browned and cooked through, about 5-7 minutes. Drain excess fat if necessary.

Stir in the sliced bell pepper, zucchini, and cherry tomatoes. Cook for another 5-6 minutes until the vegetables are tender.

Season the mixture with oregano, basil, salt, and pepper. Stir well to combine.

Remove from heat and sprinkle with crumbled feta cheese and chopped parsley before serving.