Fill a large nonstick saucepan (at least six quarts) with 12 cups water; add oil and salt. Cover and bring to a brisk boil over high heat.
Add the rice and continue cooking over medium to high heat, stirring occasionally.
After three to five minutes, use a slotted spoon to scoop some grains from the water. Break one grain in half to make sure it is al dente. Turn off the heat and pour rice into the colander to drain; set aside.
Place the empty six-quart saucepan back onto the stovetop over medium heat. Add a quarter-inch canola oil and two tablespoons water. Add turmeric and/or saffron powder. Stir together.
Add the drained rice and shape it into a pyramid. Cover the pot and cook for five to seven minutes until rice begins to steam.
Uncover and place two paper towels (one on top of the other) over the rice. The ends will extend outside the pot. Replace the lid tightly.
Reduce heat to low and simmer, covered, for 45 minutes. Turn off the heat and tilt the lid until ready to serve.
With a wide spatula, scoop the rice from the pot, making sure to not disturb the crust (tadig) that formed on the bottom of the pot. Serve the rice on a flat serving platter, mounding it into the shape of a pyramid. Turn the tadig out onto a flat serving platter by inverting the pot, as you would invert a cake pan, or cut it into pieces and serve around the rice.
Mix together one teaspoon crushed saffron threads and a quarter cup hot water. Steep for a few minutes, until the water becomes yellow.
Mix saffron water with steamed white rice. Use this intensely yellow rice to make designs on the Chelo.
To reheat this rice: Pour half a cup water mixed with a quarter cup canola oil onto the pyramid in a large pot. You can also freeze this rice, as long as you do not stir it until it is completely defrosted. You can even cook it, freeze it, and later steam it as it defrosts! I know I will have to spend time in “rice hell” for admitting to freezing Persian rice, but it is worth it just to make our lives easier!