1. Heat vegetable oil in a nonstick skillet, over medium heat. Saute onion and serrano pepper until softened, about 1-2 minutes. Season with salt and black pepper.

2. Add tomato, and cook for 1 minute.

3. Add eggs, cracked one at a time, on top of the onion tomato mixture. Continue to cook, stirring constantly, until eggs are cooked to taste, about 3 to 4 minutes.

4. Serve immediately with warm tortillas or crumbled tortilla chips over top.