Heat 2 tablespoons of extra virgin olive oil in a large skillet over medium heat. Allow the oil to warm for about 30 seconds until it shimmers slightly. Starting with properly heated oil helps prevent ingredients from sticking and allows the onions to cook evenly. Avoid using high heat, as it can cause the olive oil to lose its delicate flavor and may burn the aromatics later in the cooking process.

Add the sliced red onion to the skillet and cook for 3–4 minutes, stirring occasionally, until the onions soften and become translucent. This step builds the flavor foundation of the entire dish. The onions should become tender and slightly sweet but not deeply browned. If they begin to cook too quickly, reduce the heat slightly and continue stirring to ensure even cooking.

Stir in the minced garlic, turmeric, cumin, oregano, and black pepper. Cook for about 30 seconds, stirring constantly, until the mixture becomes fragrant. You'll notice the warm aroma of the spices and garlic filling the kitchen. This brief cooking time allows the spices to bloom in the olive oil, enhancing their flavor throughout the dish. Be careful not to let the garlic brown, as it can quickly become bitter.

Add the lean ground beef to the skillet. Using a wooden spoon or spatula, break the meat into small, even crumbles as it cooks. Continue cooking for 7–9 minutes, stirring occasionally, until the beef is fully browned and no pink remains. For the best flavor, allow the beef to sit undisturbed for a minute or two between stirring so it develops a deeper caramelized color. If excess grease accumulates, carefully drain it before proceeding.

Stir in the sliced zucchini and halved cherry tomatoes. Cook for 5–7 minutes, stirring occasionally, until the zucchini becomes tender while still maintaining a slight bite. The cherry tomatoes should soften and begin releasing their juices, creating a light, naturally flavorful sauce that coats the beef mixture. Avoid overcooking the zucchini, as it can become mushy and release too much moisture into the skillet.

Add the spinach or kale to the skillet and gently stir it into the warm beef and vegetable mixture. If using spinach, cook for 1–2 minutes until just wilted. If using kale, allow 3–4 minutes for the leaves to soften. The greens should retain their vibrant color while becoming tender enough to blend seamlessly into the dish.

Remove the skillet from the heat and immediately stir in the crumbled feta cheese. The residual heat from the skillet will slightly soften the feta without causing it to fully melt, creating creamy, tangy pockets of flavor throughout the dish. Mixing it in after removing the pan from the heat helps preserve its texture and distinctive taste.

Sprinkle the skillet with fresh chopped parsley or mint, depending on your preference. If desired, add a fresh squeeze of lemon juice over the top to brighten the flavors and balance the richness of the beef and feta. The fresh herbs and citrus add a refreshing finish that enhances the Mediterranean character of the recipe.

Taste the skillet and adjust the seasoning as needed. Add additional salt and black pepper gradually, tasting after each adjustment. Since feta cheese naturally contributes saltiness, it's best to season conservatively and make final adjustments only after all ingredients have been combined.

Serve the skillet warm and enjoy immediately. This dish pairs beautifully with cauliflower rice, a simple side salad, roasted vegetables, or can be enjoyed on its own as a satisfying one-pan meal. Leftovers also store well, making it a wonderful option for meal prep and easy lunches throughout the week.