In a small bowl, use a fork to whisk together the egg, onion powder and dried thyme.
Warm the oil in a small pan and pour the whisked egg into the pan, ensuring it reaches all the edges. If you end up with some raw egg on top, simply tip the pan a bit while lifting the edge or your omelet so that the raw egg can run underneath at the edge.
Flip the omelet and add cheese. Let it cook for just just long enough to warm the cheese, and fold in half.
Slide onto a plate and serve.
Please note that the nutrition data is a ballpark figure. Exact data is not possible.