1. Preheat the oven to 375°F.
2. Generously spray a 12-cavity muffin pan with cooking spray.
3. Heat the extra-virgin olive oil in a large frying pan over medium-high heat.
4. Add the lean ground beef.
5. Cook the beef, breaking it up as it cooks, until no longer pink.
6. Stir in the taco seasoning until well mixed.
7. Remove the pan from the heat.
8. Stir in the salsa.
9. Set the beef mixture aside.
10. In a large bowl, whisk together the eggs, egg whites, salt, and black pepper.
11. Use a ladle to divide the egg mixture evenly between the 12 muffin cavities.
12. Divide the beef mixture between the muffin cavities, using about 2 tablespoons per cavity.
13. Top each muffin cavity with 1 lightly heaping tablespoon of reduced-fat Mexican cheese blend.
14. Bake for 20 to 23 minutes, until the eggs are set and lightly golden brown.
15. Let the muffins cool in the pan for 10 minutes.
16. Remove the muffins to a wire rack to finish cooling.

Storage and Reheating

Store cooled egg muffins in a lidded container in the refrigerator for up to 4 days.

Freeze cooled egg muffins for up to 3 months.

Reheat in the microwave for 30 seconds to 1 minute.

The muffins can also be eaten cold.