In a separate pan, bring water to a boil and add the spaghetti along with a pinch of salt. Boil for about 8-10 minutes or until noodles are soft to taste.
Add your thinly stripped ham to your pan with olive oil and stir occasionally until the edges slightly brown. You can also add your onion slices here (though they are optional)
Add your flour and water or milk and stir until it makes a semi thick paste. Then add your salt and pepper.
Add your parmesan and stir. Then add your noodles and mix everything well