Cut the pork into chunks and season them heavily with salt, pepper, and oregano.

Put them in a heavy pot with the cup of oil, the Coke, the quartered orange, cinnamon sticks, and bay leaves

Simmer, uncovered, for at least two hours

Remove the orange peels, cinnamon sticks, and bay leaves

Turn up the heat and continue cooking the meat until it darkens and becomes very tender and crisp on the outside

Remove the meat and shred it. Serve on tortillas.