Heat the oil in large pot over medium-high heat. Add the onion to the pot along with the sea salt. Sautee until the onion is translucent and fragrant, about 5 minutes.
Add the garlic and cook for another minute or two, then add the rice. Toast the rice a little, stirring frequently. The rice will have a toasted, nutty fragrance.
Add the stock, tomatoes an their juices, oregano, and red pepper flakes, if using, to the pot and bring to a boil. Reduce the heat to a simmer and cover.
Let cook for approximately 45 minutes, or until all of the liquid has been absorbed by the rice.
Fluff the cooked rice with a fork. Top with the parsley or cilantro, and serve hot.