Spanish potato and onion tortilla

Name: Spanish potato and onion tortilla
Prep time: 20 min
Cook time: 35 min
Total time: 55 min
Yield: 2 servings
Cuisine: Spanish
Ingredients: 300 gr of Baking potato; To taste Black pepper; 2 tbsp of Extra virgin olive oil; To taste Fine sea salt; 5 Medium egg; 1 White onion