Creating a perfect cheesy mushroom omelette is easier than you might think! Follow these simple steps for a guaranteed delicious result every time:

1. Prepare the Mushrooms and Onions: Start by cleaning your mushrooms. If using button or cremini mushrooms, you can gently wipe them clean with a damp paper towel. For more earthy mushrooms like shiitake or oyster, trim any tough ends. Slice all the mushrooms into even pieces, about ¼ inch thick. Finely chop the onion and mince the garlic. Having all your ingredients prepped and ready to go will make the cooking process smooth and efficient.
2. Sauté the Mushrooms and Onions: Heat 1 tablespoon of butter in a non-stick frying pan over medium heat. Once the butter is melted and shimmering, add the chopped onion. Sauté the onion for about 3-4 minutes, or until it becomes softened and translucent. Next, add the minced garlic and cook for another minute until fragrant, being careful not to let it burn. Add the sliced mushrooms to the pan. Increase the heat slightly to medium-high and cook the mushrooms for about 8-10 minutes, stirring occasionally, until they are tender, have released their moisture, and are starting to brown slightly. Season the mushroom mixture with salt and black pepper to taste. Once cooked, remove the mushroom mixture from the pan and set aside in a bowl. Wipe the pan clean with a paper towel – this step is important to ensure a clean pan for cooking the omelette.
3. Prepare the Egg Mixture: In a medium bowl, crack the eggs. Add the milk or cream, a pinch of salt, and a pinch of black pepper. Whisk the eggs vigorously until the yolks and whites are fully combined and the mixture is light and slightly frothy. Over-whisking can make the omelette tough, so whisk just until combined.
4. Cook the Omelette: Place the same non-stick frying pan back over medium-low heat. Add the remaining 1 tablespoon of butter and let it melt and coat the bottom of the pan evenly. Pour the whisked egg mixture into the hot pan. Let the eggs cook undisturbed for about 1-2 minutes, or until the edges start to set and the bottom is lightly cooked but the top is still slightly wet.
5. Add the Mushroom Filling and Cheese: Using a spatula, gently lift the edges of the cooked egg and tilt the pan so that the uncooked egg mixture flows underneath and comes into contact with the hot pan. Repeat this process around the edges of the omelette until most of the liquid egg has set but the center is still slightly soft and creamy. This technique ensures even cooking and a tender omelette. Sprinkle the cooked mushroom mixture evenly over one half of the omelette. Then, sprinkle the grated cheddar cheese generously over the mushrooms.
6. Fold and Finish: Gently fold the plain half of the omelette over the mushroom and cheese-filled half using your spatula. Cook for another 1-2 minutes, or until the cheese is melted and gooey and the omelette is heated through. Be careful not to overcook the omelette, as it will become dry and rubbery. You want it to be slightly moist and tender in the center.
7. Serve Immediately: Slide the cheesy mushroom omelette onto a plate. Garnish with fresh chopped parsley or chives for a pop of colour and freshness. Serve immediately while it’s hot and the cheese is beautifully melted and gooey.