Par-boil the potatoes (around 10 minutes), drain and allow to cool. Heat the oil in a large frying pan (If the bacon includes a lot of fat, reduce the oil quantity accordingly) and fry the bacon until slightly crispy. Remove the bacon and put aside.
Fry the onion in the same oil until translucent. Remove the onion and put aside.
Add the potatoes in a single layer and fry without stirring for around 5 minutes. Sprinkle on a little salt and pepper, turn the potatoes over, return the onion and bacon to the pan and brown the other sides of the potatoes.