Preheat the oven to 450F. Peel and chop potatoes and dice onion.
In a non-stick pan, or cast iron skillet, heat olive oil on medium-low heat. Add potatoes first then season well with salt and pepper. Place chopped onions on top.
Cook on low to medium-low heat for 15 to 20 minutes covered, stirring often, softening potatoes and onions, but not browning them too much.
Let potatoes cool. Oil a 9" to 10" baking dish or pie plate. Add potatoes.
Beat the eggs and pour over potatoes. Bake for 15 minutes. Then turn heat down to 300 degrees and continue baking another 30 minutes.
Let cool. Serve from baking dish, or turn onto a platter and cut into small slices or cubes. Served best when warm.