Drain the cans of tuna into a fine sieve with a bowl underneath, gently flake the tuna to remove any excess oil
Heat a medium sized non stick fry pan with a medium heat and add in 2 tbsp (30 ml) of the olive oil from the canned tuna
In the meantime, finely chop the onion
Once the oil is hot add in the onion, mix with the olive oil every minute or so that way the onion evenly sautees
While the onion is cooking, crack the eggs into a large bowl, add in the chopped parsley and season with salt & pepper, mix together until well mixed
After 4 to 5 minutes and the onion is lightly sauteed and translucent, remove from the heat, add the onion into the bowl with the eggs, also add in the drained tuna, mix together and let it sit so the flavors can develop
At the same time, heat the same pan with a low medium heat and add in 1 tbsp (15 ml) of the olive oil from the canned tuna
After letting the egg mixture sit for 3 minutes, add into the hot pan, gently mix so everything is in a flat layer, then cook without mixing
After 4 to 5 minutes run a spatula through the outer edges, this is to ensure the omelette is not sticking to the pan, then using a plate that is slightly smaller than the pan, place it over the pan and in one swift move flip the pan into the plate, slide the omelette back into the pan to cook the otherside, using the back of the spatula compact the omelette from the outer edges towards the center, cook for another 4 to 5 minutes or until the eggs are cooked through, then remove from the heat and slide into a serving dish, serve warm, at room temperature or even chilled, enjoy!