Steps
1. Heat some olive oil in a non-stick skillet over medium heat.
2. Add the sliced potatoes and onions to the skillet and cook until they are golden brown and tender, about 8-10 minutes.
3. In a mixing bowl, whisk together the eggs, salt, and pepper.
4. Pour the egg mixture over the potatoes and onions in the skillet.
5. Sprinkle the shredded cheddar cheese and diced tomatoes evenly over the egg mixture.
6. Cover the skillet and cook for about 5-7 minutes, or until the eggs are set.
7. Remove the lid and let the frittata cook for another 2-3 minutes to lightly brown the top.
8. Carefully slide the frittata onto a serving plate and cut into wedges.
9. Serve hot and enjoy!