Begin by bringing the chicken stock to a simmer.
Cut the chicken breasts into thin strips, about 1/2 inch thick. Place on a dish and sprinkle the flour over the chicken until all of the strips are completely coated.
In a large saute pan, heat a large drizzle of olive oil over medium to high heat. Shake off the excess flour from the chicken strips and add into the saute pan. Mix the chicken strips to cook evenly for about two minutes and then add in the garlic. Continue to stir together for another minute.
Reduce the heat to medium and pour in the wine or half cup of chicken stock and mix together. Add in the tomatoes and the spinach and mix for about a minute until the spinach begins to shrink a bit.
Reduce the heat and place the spaghetti down the middle of the pan and lightly drizzle with olive oil. Season with salt and black pepper. Add in three to four cups of chicken stock into the pan, or enough to just cover the pasta. Bring the chicken stock to a boil and then reduce the heat to a slow simmer. Cover the pan with a lid and let cook for a couple of minutes, making sure to stir occasionally until the chicken stock has been absorbed so that the ingredients do not get stuck to the bottom of the pan.
Once the chicken stock is mostly absorbed, taste one of the spaghetto to see if it is cooked to your liking. If it is still under cooked, add in another cup of chicken stock and cover with the lid again. Once the chicken stock is absorbed, check again if the spaghetti is cooked enough. Repeat with adding half a cup of chicken stock until your spaghetti is cooked to your liking.
Once the spaghetti is cooked, remove the pan from heat. Serve with a sprinkle of pecorino cheese on top and enjoy! Salute and cin cin!