After cutting the potatoes I put them in boiling oil in a pan and then mix them while they get cooked, but it takes like an hour and they hardly become crispy.
I don't have an oven so all I can use is a stove. What can I do to make them crispy?
We have crispy "little fried potatoes" every week with omelettes. Chop the spuds the size of dice - important to get them all approximately the same size. Different potato varieties give different results/timings. Maris Piper are good. Microwave the diced spuds for 4 minutes in a bowl. They come out a bit hot and sticky - separate them and add to a non-stick pan with plenty of hot oil over a medium-hot flame and keep turning them. About 6-8 minutes they will be crispy. After 10 minutes they can be TOO crispy/burnt, so watch the pan.
At the crispy stage you can make instant "patatas bravas" by pouring off the excess oil, reducing the heat and adding a teaspoon of hot chili sauce plus as much tomato ketchup as you like to dilute the chili.
I fry my chips in two goes:
If you 'parboil' them first, so boil them for about ~10 minutes - long enough for them to go a little bit soft but not fully cooked and then drain them and allow them to cool for a little while. Also cover them in a little bit of dripping / fat which will allow the outsides to really crisp up nicely.
If you are cutting the potatoes thin enough you can probably omit the parboiling and cover them in a little bit of fat / dripping and then fry them up and they shouldn't take long to cook at all, but the sort of pre-cook process makes the centers cooked so you wouldn't have to wait as long for them to be cooked in the oil.
Yet another method is similar to the one you have mentioned - I am not sure how much oil you are referring to but you can make a make-shift deep fat fryer, just fill the pan with enough oil to cover all of the potato cuttings and heat the oil up so it's nice and hot (boiling) and drop in your parboiled potato bits - I've done this after a disaster with an old deep fat fryer and the result was some of the nicest chips I've had, albeit rather greasy. A way top reduce the grease is to allow them to sit on some kitchen towel which should soak up any of the excess oil but does leave them a little cold afterwards.
Hope this helps.