Cook sliced onions on high heat, then turn to low heat and let cook until the crispy edges turn soft and caramel-y. This process takes around 10-15 min.
Once onions have cooled down a bit, add them to the already dressed pasta.
Transfer to a serving bowl and top with the crumbled feta. (I like buying a block of cheese and crumbling myself)
Lastly, top with an extra sprinkle of oregano over the dish. It not only adds flavor, but adds to the presentation.