Heat the olive oil over medium heat in a large skillet, frying pan or sauté pan. Add the potato slices and stir to coat with oil. Cook for about 5-7 minutes, stirring occasionally.
Add the sliced onions and crushed garlic. Mix well and continue cooking for another 10 minutes – stirring occasionally.
Add the ham strips and sliced jalapeños, mix and cook for another 5 minutes or until the potatoes are tender. Taste and season with salt – the ham is naturally salty so you probably don’t need to add much salt.
Remove from the heat and let the potato ham mix cool for about 5 minutes.
Pre-heat the oven to 375F.
Beat eggs with some ground black pepper using a whisk or fork until you have a smooth mix.
Add the potato ham mix to the eggs and stir gently.
The tortillas can be baked in greased baking molds or an oven proof skillet(s). For easy removal, you can line the baking mold with parchment paper.
Pour the tortilla mix into the baking molds and place in the pre-heated oven.
Bake the potato and ham tortillas until they are fully cooked and they start to get golden on top. Exact baking time will vary based on the size of the baking pan and thickness of the tortilla. The smaller ones made in 5 inch cast iron pans (at less than 1 inch of thickness) took about 18-20 minutes to be done. The larger one made in a rectangular 9 inch by 5 inch pan , and about 1.5 inch thick, took about 30-35 minutes to be done.
Remove the baked Spanish tortilla from the oven. Let it cool down a little before removing from the baking mold. If lined with parchment paper you can just gently lift it out of the pan. If prepared in small individual serving molds then they can be served directly as is. Can be served warm or cold.
Sprinkle with chopped parsley (or cilantro) and crumbled queso fresco.