01 - Preheat oven to 375°F. Lightly grease a small 1-quart oven-safe baking dish with olive oil or cooking spray.
02 - Heat 1 tablespoon olive oil in a skillet over medium heat. Add minced garlic and sauté for 30 seconds until fragrant, being careful not to burn.
03 - Add chopped baby spinach to the skillet. Sauté for 2–3 minutes, stirring frequently, until completely wilted. Remove from heat and let cool for 2–3 minutes.
04 - In a large mixing bowl, combine crumbled feta, softened cream cheese, Greek yogurt, and half the shredded mozzarella. Mix thoroughly until mostly smooth and well incorporated.
05 - Fold in the cooled sautéed spinach, sliced pepperoncini, dried oregano, red pepper flakes if using, and black pepper. Mix until evenly distributed throughout the cheese mixture.
06 - Transfer the dip mixture into the prepared baking dish, spreading evenly. Top with remaining mozzarella cheese and drizzle with the remaining 1 tablespoon olive oil.
07 - Bake for 20–25 minutes until the dip is bubbling around the edges and the top is lightly golden brown.
08 - Remove from oven and let the dip rest for 5 minutes to set. Sprinkle with fresh chopped parsley or dill and serve with lemon wedges on the side.