Heat 1 tablespoon of olive oil in a pan over medium heat. Sauté the onion until caramelised, for about 7-10 minutes. Add in the garlic, stir for one minute and then add the spinach. Cover the pan with a lid for about 2 minutes or until the spinach is wilted. Add the dill and stir. Remove from the heat and let it cool for 5 minutes.

Add the feta cheese, lemon zest, salt, fresh pepper and mix well. Place a 30×30 cm piece of aluminum foil, on your counter. Grease it, season with salt and pepper and place the chicken on it (ask your butcher to pound the chicken until its about 1- 1/2 cm. thick). Sprinkle salt and pepper on the chicken and spread the cheese-spinach mixture all over the chicken. Wrap the chicken carefully, so that the filling doesn’t escape. Finally, wrap the foil around the chicken. Twist the edges of the foil and shape it into a large candy.

In a pan sauté the chicken over medium to high heat. Cook the chicken, twisting it occasionally, until browned and cooked through, for about 10-12 minutes. Let the meat rest for 3-5 minutes before slicing it and remove the tinfoil. Cut it into slices and serve with pasta, mashed potatoes, vegetables or rice.