Heat 1 tsp oil in a pan and add jeera. Add mashed potato, turmeric and salt. Mix well and keep aside.
In a bowl, add ragi flour, wheat flour and salt. Add remaining oil and mix well.
Add warm water little by little and knead into a soft dough. Cover and rest the dough for 10 minutes.
Roll the dough into a thin rectangle. Spread the potato mixture evenly over it.
Roll tightly into a log shape. Cut into round spin wheels.
Heat a tawa and cook the spin wheels on low flame with little oil. Flip gently and cook until both sides are well cooked.