Put the spaghetti to boil in a pot with water and a pinch of salt. While they cook, prepare the carbonara sauce.
Step by step
Heat a splash of oil in a frying pan and fry the finely chopped onion. Chop the walnuts and add them to the pan when the onion begins to brown. Stir the ingredients for a couple of minutes.
Add the nut drink and raise the heat until it reaches the boiling point. Add salt and nutmeg to taste and leave it on the fire for about five minutes, stirring constantly. You can serve the sauce like this or pass it through the blender to make it finer.