Preheat the oven to 350 degrees F.

Heat the avocado oil in a large oven-safe skillet and add the chopped potatoes. Cook, stirring regularly, until the potatoes begin to look golden-brown, about 5 to 8 minutes. Add in the sliced onions and continue cooking, stirring constantly, until the onions are translucent, about another 5 minutes. Stir in the garlic.

In a mixing bowl, whisk together the eggs, sea salt, and pepper until well-beaten.

Pour the beaten egg mixture into the skillet, evenly coating the potatoes and onions.

Immediately transfer the skillet to the preheated oven and bake for 18 to 22 minutes, or until omelette reaches desired doneness. Note: it’s fine if the omelette bubbles up in certain areas - this is normal, and it will fall back down once it cools.

Remove omelette from the oven and allow it to cool for at least 15 minutes before slicing and serving.