Once the oil is hot, add the onion and cook for about 5 minutes until it begins to brown and caramelize, stirring every minute or so. If getting too dark or burnt around the edges, turn the heat down.

Once the onion begins to brown, add the red pepper. Cook, stirring frequently, until the pepper begins to soften, about 3 more minutes.

While cooking the pepper and onion, break the eggs in a bowl and mix together with a whisk or fork until lightly frothy.

Mix the fresh herbs, salt, pepper and spinach into the egg.

Once the pepper is soft, pour the egg mixture into hot pan. Fold occasionally with a heat-resistant spatula. If egg is turning brown, turn down heat. Do not over-stir, as this will result in a non-fluffy egg.

Once egg is almost cooked through (not runny), turn off the heat. Sprinkle the cheese over the top of the eggs and vegetables, cover with lid or foil and let sit for about 1 minute to melt.

While the cheese is melting, warm the tortillas.

Distribute the filling amongst the 4 taco shells and enjoy immediately. You may choose to top with salsa.