In a pot with water, start heating water, when it is boiling, add the pasta and let it cook for 10 to 12 minutes.
While the pasta is cooking, prepare the sauce. Put the bacon cut into strips in a large skillet and cook over high heat (do not add any oil as the bacon has a lot of fat and will cook in its own juices). After a couple of minutes, when it has toasted, remove the bacon from the skillet, leaving all the fat it has released in the skillet.
Now, in this fat and on a gentler heat, add the finely chopped garlic cloves, after a couple of minutes, when the garlic starts to color, add the diced chicken breast. Raise the heat and mix frequently, to seal the chicken, keeping it still raw inside.
After two minutes, add the milk, the cooking cream, 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 they blend well.
If you see that the pasta is not creamy enough you can add cream or chicken broth. Also add the chopped parsley and mix again until the pasta has achieved that creamy touch we are looking for. And done. Serve hot.