Warm the olive oil in a large pan over medium heat and soften the diced onions for about 5 minutes.
Add the garlic, oregano, cayenne, and ground cloves, cooking together for an additional minute to release their aromas.
Pour in the chopped tomatoes, vegetable stock, and balsamic vinegar, bringing the mixture to a boil before lowering the heat to a gentle simmer.
Let it cook for 7 to 10 minutes, stirring occasionally until the sauce thickens.
Fold in the drained chickpeas, packed spinach, and crumbled feta cheese, then cover and simmer for 2 to 3 minutes until the spinach wilts.
Season with salt to taste, sprinkle with red chili flakes and fresh parsley if desired, and serve warm.