Cook the potatoes, and peel and chop them to half inch chunks.
In the meantime, cook pasta according to package directions and set aside.Heat oil in a pan over medium flame. Add the onions and sauté for 3-4 minutes until they turn translucent. Add the chopped potatoes, salt and cayenne, cook for another 3 minutes.
Add the cooked pasta, combine well and sauté for 3 more minutes.