- Crack eggs in bowl and add salt and pepper. Whisk until fluffy.
- Melt butter in a small frypan and add in the onions and mushrooms. Cook until onions are translucent and mushrooms soft.
- Pour the eggs into the pan and cook on medium.
- When the eggs begin to get firm, sprinkle cheese on top.
- With a spatula gently fold the omelet in half. Cook a little while longer then remove from heat.