What's Your Favorite Omelette Filling?

There's nothing like whipping up a delicious omelette for a quick dinner. We all have our list of ingredients that turns an omelette from yum to scrumptious. What's your omelette filling secret?

photo credit: Omlette via photopin (license)

Here's mine:

• thinly sliced tomatoes
• thinly sliced mushrooms
• thinly sliced olives
• a generous sprinkle of cheese