Start by heating a tablespoon of avocado or coconut oil over medium-high heat, and sautee the chicken with the onion for about 5 minutes.
Add the salt pepper, and cumin to taste, and a little bit of chopped cilantro, and let cook for another 3 minutes or so.
Combine the above mixture with the mayonnaise, and set aside.
To put the flautas together, warm up the tortillas and fill each with the chicken mixture before rolling them up and sticking a toothpick through them to keep them from unrolling.
Add the rest of the oil and lower to medium heat. Cook each flauta in the hot oil for a couple of minutes, or until golden brown. Use tongs to remove from the skillet, putting them in a large bowl or a paper towel-lined plate.
You can then pat away any excess oil before putting them on a plate and covering them generously with lettuce, pico de gallo, feta cheese, and salsa.