Heat the oil in a pan. Add the rice and sauté until translucent, stirring continuously. Gradually pour in the soup and water, stirring frequently. Ensure that the rice is always just covered with liquid. Simmer for approx. 20 mins. until the rice is creamy and al dente.
Dry-roast the nuts in a frying pan for approx. 3 mins. Stir the manchego into the risotto, sprinkle the nuts on top.