That is an excellent tip. I suppose this will vary depending on the number/size of potatoes, size of pot and power of hob jets though? I will definitely play around with those settings though 
Sorry Goncalo, I hadn't seen your follow up questions.
Yes, everything will always depend on your own settings.
Timings will vary depending primarily on the size and type of potatoes you will use, burner size, pot size and so on, even if you use salt in the water or not! Naturally smaller potato pieces will cook faster to 'doneness' that larger ones will. Just experiment a little till you find the right settings for you.
One more question, when it starts boiling and you start your counter for 6/7 minutes, do you lower the heat from the moment they start boiling?
Yes.
I bring water to the boil (sometimes if I'm in a hurry I boil water in a kettle first and use that, but it's better to boil from cold in the pan in my opinion) once it's boiling I add the chopped, rinsed (always worth rinsing chopped potatoes in cold water to get rid of possible starch) and strained potatoes to the water. The water will then go off the boil as the cold potatoes are added. I then add a pinch of salt and turmeric and then bring them back to the boil. As soon as they start boiling I drop to a simmer, put the lid on and start timing. As I mentioned, on my hob, 10 mins is usually done, so I simmer for about 6-7 mins.
Also, regarding maris pipers, I can't easily source them here in most super markets. I suppose potatoes is something we have in different varieties around here (I think the irish are known for their potatoes) but either they exist and aren't tagged as such, or there is no tag at all, which is more often than not the case.
Ahh okay. Well Ireland is the place for potatoes!
You want a floury type rather than waxy, but not so floury they disintegrate. I find Maris Pipers and King Edwards to be pretty good all round potatoes.
Just experiment till you find a variety you like really.
I never had the methi aloo, but I'm sort of curious. The aroma from methi used to make me feel pretty sick, but I think it's grown on me. Same for cumin, so I'll try it some time -- maybe the methi gosht that has been discussed recently 
I love Aloo Methi, it's by far my favourite vegetable dish and I always ask for it in any Indian Restaurant I go to even if they don't have it on the menu - more often than not they just nod and up it comes. It's just another of those little tests, if they've never heard of it or don't know how to cook it, it's not a good sign!
In my opinion Methi/Fenugreek is probably the most important ingredient to capturing that BIR smell and taste. Just smell some ground fenugreek and compare that smell to the smell you get from inside an Indian Takeaway bag, both the smells are very close together.
Understanding Fenugreek in all its forms, seeds, ground, dried/fresh leaves is really key to achieving BIR flavour in my opinion.