Potatoes: They are as stubborn as any vegetable ever gets on the fire, and trying to hurry them up is nothing but an exercise in futility: in the gas range they'll just keep mooning you, and in the microwave you'll end up with a leathery pouch full of the most disgusting heat-dried flour.
Therefore, I'll explain the way I do them, which I adapted from my grandmother's own way on the gas range.
By the way, my grandmother would always say one thing about potatoes: if you have time to cook one, better cook three. In the gas range it wasn't so obvious, but its just a lot more obvious nowadays. My own rule-of-thumb is The time it takes to cook three potatoes is slightly less than twice what it takes to cook a single one, subtracting the time it takes for the water to come to the boiling point. this rule also applies to rice: I make a single cup in 17 minutes, but two in 25 and three in 32.
Anyway, all done, this instructable shouldn't take more than 20 minutes.
Step 1: Select and wash the potatoes and the pot
A microwave-safe cooking pot, as close to the size of the potatoes as possible
A microwave oven
Select the potatoes you'll need. In keeping with my grandmother's wisdom, I'm preparing three, and for demonstration purposes I'll pick them unevenly sized. It is possible to cook them together as long as the largest isn't more than twice as heavy as the smallest.
The small one I want now: I'm hungry; the medium one might be part of tomorrow's lunch; the large one is definitely for tomorrow's dinner, as I'll be making some soup.
So, select potatoes that aren't too unevenly sized, then arrange them evenly inside a pot. Try to select one that hugs them snugly, but where the water would still cover them (even if barely). The first image reflects this, although not as well as the images on the following step.
Drip dry them and the container. Don't waste paper.
Additionally, if you want to peel them, do so now.