Add rice to a bowl and rinse it well a few times. Then pour 1½ cups water and ½ teaspoon salt. Keep it in a pressure cooker. Pressure cook rice for 3 whistles until soft. You can also cook the rice directly in the cooker for 2 whistles.
When the pressure releases, remove the rice & mash it lightly. You can also fluff up & use if you do not like mushy rice. If you prefer to use milk, refer my notes below. Cool it completely.
Add curd to cooled rice. Mix well until combined. If you have cooked the rice without salt, then add it now.
Stir in coriander leaves, grated carrots and cucumbers to the curd rice. Taste the curd rice & add more salt if needed.
How to make curd rice
Heat oil in a pan. Then add cumin & mustard. When they begin to splutter, add red chilli, chana dal, urad dal & cashews if using. Fry until the dal turns golden.
Add ginger, green chili and curry leaves.
When the curry leaves turn crisp, add hing and turn off the stove. If using bottle gourd, add it to the hot seasoning and stir.
Pour the tempering to the curd rice and mix. South Indian style curd rice is ready.