Spanish tortilla redux

In a previous posting, I talked about making a Spanish tortilla (that potato egg dish that is a staple of Spanish cooking). In previous incarnations, I used potatoes that had been boiled and then allowed to cool. That of course is not the way it should be done, but is quite handy if you have some cooked spuds lying around. The "real" way of doing a tortilla is to poach the potatoes in oil. How much difference does this make you might ask? How greasy will it be? The answers are simple. It makes a huge difference and it isn't greasy. So this will be the way from now on.
Ingredients
2 cups olive oil (not extra virgin, just a good quality oil)
4 medium yukon gold potatoes, peeled and sliced thinly
1t kosher salt
1/2 medium yellow onion sliced thinly into rings
5 large eggs
a couple of threads of saffron (steeped in the eggs)

Method
In an 8" non stick pan bring the oil up to a suitable temperature over a medium flame. Suitable here is when you see viscous threads in the oil, but it won't brown a bread cube. This is not a frying process, but a poaching process. Meanwhile salt the potato slices lightly. When the oil is at temperature, slide the potato slices in to the pan, and poach lightly for about 15 minutes - until the potato slices are soft. Do not allow the potatoes to brown. Add the onion slices, again allow to poach with no browning. When the onion is cooked, remove the potatoes and onion from the pan. Drain the oil and stir for a future use.

Beat the eggs with a little salt/pepper. Add the drained potatoes and onions back to the pan, and turn the heat to medium. Allow to warm. When warmed, pour the egg mixture over the potatoes and onions - cook until just set.

Allow to cool to room temp and server