The word should be spelled as Tahdig

A popular Persian way of preparing rice.

2 medium size potatoes
2 cups Basmati rice
1/3 cup vegetable oil
salt (as desired)

Peel and slice the raw potatoes into 1/2 inch thick slices.

Rinse & drain rice. Bring 4-5 cups of water to a boil in a 3 qt pot, add salt if desired. Add rice & continue to boil the water, stirring occasionally, for about 10 minutes. Check to be sure that the rice doesn't cook completely at this point.

When rice is roughly half cooked, drain into a colander. Pour 1/4 cup of cooking oil into the pot and lay the potato slices in the bottom close together in a single layer. Add a small amount of salt (if desired). Layer the half cooked, drained rice loosely atop the potatoes. Place pot on stove over medium high heat for 4-5 minutes or until rice begins to steam. Lower heat & add 5 TBSP of water & 2-3 TBSP of oil on top of rice. Cover & let simmer for about 1/2 hour or until cooked and tender. The higher the heat, the crunchier the Tahdig. Scoop out the rice & use a soft spatula to remove Tahdig at bottom, or try to make the contents of the pot come out as an entire cake of rice on the serving dish.

Tahdig can also be made by substituting the potatoes with bread (for ex. pitta or Lavash) or with the rice alone. Other common additions include slices of onion, beet or other rootstock.