Tortilla y ya!

I did it. I nailed the tortilla. Or at least I made a version of it that both tasted great to me and impressed a flamenco guitarist who grew up on the real thing.
Here's how I did it:
Four small to medium Yukon potatoes, washed but not skinned. Cut in half, then again, then sliced from there.
One medium onion, sliced
two garlic cloves, diced
a cup of oil. Olive oil is fine, but corn oil is more flavorful it seems.
Six eggs, lightly whisked.
A dollop of milk.
A bit of chopped parsley. A tablespoon at most.

Heat most of the oil into a NONSTICK SKILLET. If you don't have a non-stick skillet, your tortilla won't turn out. I don't know how women in Spain did it before this invention, but thank God I live in the plastic age.
Add the garlic and onions - saute for a bit, then add the potatoes. Stir once or twice to cover the potatoes in oil, then don't touch again. Cover
Ccook for about 20 minutes. Don't brown. But a little brown is always ok.
Drain the potatoes. I remove them with a slotted spoon.
Whisk your eggs with a dollop of milk. Add salt and pepper to taste.
Add the remaining oil to the skillet and return the potato/onion mixture. Pour the eggs over this and stir once or twice to cover the potatoes. Don't forget to add your parsley.
Cover. Watch.
As it cooks, shake the pan a little every now and then to make sure the tortilla isn't sticking to the bottom.
When the eggs are almost cooked, (mostly solid except for a small pool of runniness on top) take a plate, put it on top of the pan and FLIP that tortilla. Slide it back into the skillet and cook on the other side. Five minutes or so.
Return to the plate.
Let cool for ten minutes.
Pour your glass of wine, break out your crusty bread, and make merry.
Buen Provecho. Or however you spell it.