Boil pasta in water according to the package instructions. If using white pasta, it will take about 10 minutes to cook, wholewheat pasta takes about 20 minutes. When it has cooked to the right consistency, remove the pot from the heat and drain off the pasta water. Leave it until the sausage sauce has finished cooking.
Prepare the sausage. You can either use sausage meat, or you can remove the skins off of raw sausages, and mash the meat together.
Heat some one calorie cooking spray in a pan, and add a finely diced red onion. Saute for a few minutes until the onion turns soft and translucent. Then, add finely minced garlic and saute for another minute.
Add the sausage meat to the pan, and use a fork, spoon or spatula to break it up as it cooks. I like to leave it in rather large chunks for the sake of this recipe.
When the meat has cooked thoroughly, and there are no pink bits left, add diced or sliced chorizo, and stir to combine. Add the tomato puree, ras el hanout and chopped tomatoes, and leave the dish to cook for 5-10 minutes, until the liquid has mostly absorbed. Then, add salt and pepper to taste.
For serving, you can plate the pasta and then add the sausage sauce on top. Alternatively, you can combine the sauce and pasta in a large bowl, and stir to combine.