Soak all the rice, poha and in yogurt and above for 6-8 hours and grind it into a smooth paste.
The batter should be really smooth without and courseness. Add water little by little so it the grinder can run smoothly.
Do not add too much water as mixture can become too watery. It is always easy to add water later if needed.
I use my ulta wet grinder but mixie or blenders can also be used.
Once done transfer into a clean bowl such that it fills 1/2 to 3/4 of the bowl. This allows room for it to ferment and grow.
Add required salt and mix well. You can skip this step to after it is fermented if you wish to avoid too much fermentation.
Cover and leave it in a a warm place for 8-10 hrs
Based on how well the batter has fermented add 1/4 to 1/2 tsp of baking soda right before making the dosas