Preheat your oven to 400F
Stab your potatoes with a fork, all the way around- this a) lets steam out, so your inside potato matter is drier and fluffier, and b) relieves any anxiety (possibly instilled by my mother) that an unpricked potato could explode in the oven. Bake the potatoes in their skin, directly on the oven rack, not on a pan, until they are soft when you squeeze them, then take them out, cut them in half lengthwise, and let them cool slightly. You want to work with them when they are hot, but they are positively thermonuclear when first out of the oven. Spare yourself some agony, and let them rest open for 5 minutes.
Using a spoon, scoop out the potato innards into a bowl, and mash them gently: a ricer is ideal, a pastry cutter (one of those semi-circular 5-wire gizmos with a handle cutting off the half-circle) is next best, and a regular potato-masher or fork last best. You don't want to make the potato gluey, but you do want it smooth. Mix the fluffy, smooth potato with salt, pepper, butter and cheese (cheddar is nice, chèvre is better). Spoon this back into the potato skins, and put in them on a pan, and back into the oven just long enough to melt the cheese. You can turn the broiler on at the end to crisp up the top.
So good. Eat them with everything. Dunk them in sour cream, or better yet, aioli, my new favorite condiment.
Aioli is a homemade mayonnaise flavoured with garlic. It is better and more versatile than store-bought mayo. Ideal for sandwiches, as a dipping sauce for potatoes, pizza or steamed vegetables, aioli is a cinch to make (and it really is marvelous to watch disparate and incompatible liquids emulsifying in your food processor). Here's how:
In the bowl of your food processor, grind 1/4 cup of garlic until fine. Add 1/4 cup of lemon juice, a good spoonful of dijon mustard, 1/2 tbsp of salt, a good grinding of black pepper (omit this if the appearance of speckled mayo would annoy you), 1 whole egg, and 1 egg yolk. Whizz these all together, and then slowly, with the motor running, drizzle 3 cups vegetable oil in. More traditionally, olive oil is used, but I often don't like the taste of olive oil, so I substitute a more neutral canola.
It will turn thick and white. Do the drizzling slowly, so all of the oil gets to emulsify, and you're not left with big globules of oil on the surface. The eggs act as an emulsifier, or mediator, if you will, allowing the oil to hang in suspension with the lemon juice, as a homogenous mixture. Kind of like how if you add eggs to a red-wine and olive oil dressing, you get a smooth caesar-type of dressing, instead of a vinaigrette that splits into its component parts.
Put it in a jar, and slather it on everything that will stand still long enough. Keep in mind, though, that there are raw eggs in the aioli, and so it has a definite shelf-life in a way that store-bought does not. You can cut the recipe in half, if you like. The way to halve a recipe that only calls for one yolk and one whole egg is to whisk the two, then put them in a measuring cup (or better yet, weigh them), and use only half.