Peel and chop the onion as well as the garlic cloves. Divide the chopped onion and garlic into two piles. 

Add 1 tbsp olive oil to a pan over medium heat and add one of the piles of onion and garlic to it and sauté about 5 minutes.

Add the frozen spinach and turn the heat up a bit so liquid in spinach evaporates out.

Sauté spinach with onions and garlic about 5-7 minutes until spinach is heated through. Season with a pinch of salt and pepper. Take mixture off the heat and set aside to get to room temperature.

Meanwhile, lay out the 4 chicken breasts and pound them out until they are flattened. Season with salt and pepper.

Then, add a layer of the spinach mixture on each and top that with a little bit of the feta. Do this with all the chicken breasts.

Then, gently roll the chicken breasts up and secure with a toothpick.

Using the same pan that the spinach was sautéed in, add the remaining tbsp of olive oil to the pan and place it over a stovetop set to medium heat and place the rolled and secured chicken breasts into the pan.

Let chicken sauté for about 5 minutes or until browned.

Flip rolled stuffed chicken over so the browned side is facing up.

Add in the remaining pile of onions and garlic and the Little Italy in the Bronx Sauce. Cover and let simmer for 15 minutes. 

When time is up, remove the pan from heat. Spoon a bit of the sauce over the chicken. Sprinkle on some parsley and more feta.

Serve as is or with The Rustik Oven Bread.