In a pot with water, place to heat water, when it is boiling, add the pasta and let it cook for 10 to 12 minutes.
While the pasta is, prepare the sauce. Put the bacon cut into strips in a skillet and cook over high heat (do not add anything from oil since the bacon has a lot of fat and it will cook in its juices). After a couple of minutes, when it has toasted. Remove the bacon from the skillet, leaving in the pan all the fat you have released.
Now, in this fat and on softer heat, add the finely chopped garlic cloves, after a couple of minutes, when the garlic begins to take color, add the chicken breast cut into small cubes. Increase the heat and frequently mix, to seal the chicken, keeping it still raw inside.
After two minutes, add the milk, the milk cream for cooking, the grated cheese, the bacon we had reserved, and the spaghetti, already cooked and drained from the water.
Also, add a small pinch of black pepper and mix all the ingredients, without removing them from the heat, so that they integrate well.
If you see that the pasta is not too creamy, you can add milk cream or chicken broth. Also, add the chopped parsley. Mix again until the paste has obtained a creamy touch. And ready. Serve hot.