In a medium bowl, beat 3 eggs. Then add 3 kitchen spoons of the potato and onion mixture into the eggs and combine gently without mashing the ingredients.
Heat 2 Tbl of olive oil, coating the bottom and sides of a 8-inch pan, over medium heat.
Add the mixture to the saute pan (it should fill it nearly completely) and move the mixture around gently with a spatula, as if you were scrambling eggs until the mixture begins to set.
Let cook untouched until the tortilla pulls away from the sides of the pan and, when shaken, it jiggles only in the center - about 10 minutes.
Place a flat plate over the pan and, in one swift move, flip the pan and the plate together to turn the tortilla out onto the plate. return the plan to the burner and distribute 1 tbl olive oil around the surface before sliding the tortilla back into the pan, uncooked side down.
Cook until it no longer jiggles in the middle and then turn out the finished tortilla onto a plate or cutting board.
Repeat process to make the second tortilla.