Mexican Omelet

This is a knock-off of the omelet I like best at French Roast NYC.  All amounts are poorly estimated from memory.  It tastes dramatically better with Gruyere than with any other cheese.  I'm not sure why, but I've tried it with whatever I had on hand (frequently cheddar) and it wasn't as good.

Ingredients
3 eggs
1/3 cup Gruyere, shredded (is that a normal amount of cheese for an omelet? you just want a normal amount.)
1/4 cup tomato, diced
2 tbs guacamole
salt and fresh ground black pepper, to taste

Directions

1) Whisk the eggs, salt, and pepper in a mixing cup.  Heat the skillet, and lightly oil.  I like to spray it with Pam and then melt a pat of butter onto it.  Keep the heat medium or lower so the eggs don't brown.

2) Pour the eggs into the skillet and allow to cook for about fifteen seconds.  Add shredded Gruyere, tomatoes, and guacamole on one half.  Then fold the other half of the eggs over the filling.  Cook just long enough for cheese to melt and eggs inside to finish cooking.  Serve immediately.