Cut the onion and garlic into fine cubes, the mushrooms into slices and the chicken breast into bite-sized pieces. Season the chicken. Cook the spaghetti according to the instructions on the packet.
Heat the butter and oil in a large pan or serving pan, first fry the onions until translucent and then fry the chicken well. Now add the mushrooms, ham and garlic and sear everything nicely before adding the broth. Season well with pepper and stir in the crème légère, then add the cream substitute and let it boil down.
Finally add the parsley and fold in the al dente cooked spaghetti.