Heat 2 tablespoons of oil in a pan over medium heat.
Add 3 peeled, sliced, and dusted potatoes to the pan and cook for 5 minutes.
Add 1/2 cup minced onion, 1 minced garlic clove, and 1 chopped green chili pepper to the pan.
Cook until the potatoes are tender.
In a separate bowl, whisk together 5 eggs, 1 chopped tomato, 2 tablespoons of milk, and 1 teaspoon of pepper.
Pour the egg mixture over the potato mixture in the pan.
Cook until the omelet is set on the bottom.
Add 1/2 cup chopped spinach and 1/2 cup parmesan cheese on one side of the omelet.
Fold the omelet in half, covering the spinach and cheese.
Cook until the cheese melts.
Optional: Drizzle 1 teaspoon of lime juice over the omelet before serving.