In a mixing bowl, add Potato (1 pound), Yellow Onion (1), and Salt (1/2 teaspoon). Mix until well incorporated.
In a frying pan, heat Extra-Virgin Olive Oil (3/4 cup). Add potato and onion mixture. Cook for 18-20 minutes, stirring occasionally, until potatoes are tender. Remove with a slotted spoon and transfer to a clean mixing bowl.
In a mixing jug, add Large Egg (6) and Salt (1/2 teaspoon). Whisk until smooth.
In the mixing bowl with the potato and onion, add the eggs. Mix together. Divide the mixture evenly between two containers.
Add half of the mixture back into the frying pan. Add Smoked Ham (4 slice) and Cheddar Cheese (4 slice), then pour the other half of the potato and onion mixture over top. Cook until edges are golden brown. Flip and cook a bit longer.