First of all rinse and scrub the roots thoroughly to remove any dirt or mud. Then soak them in a large bowl of salted water for 20 minutes.
Bring a large pot of salted water to a rolling boil. Add the arbi roots and cook until fork tender for 8-10 minutes. Drain.
Once cooked, peel the arbi roots and place in a bowl. Arbi roots tend to be slimy and bit mushy. To control the sliminess place the boiled and peeled arbi colocasia in refrigerator for 10 minutes.
Chop the cooked arbi into rounds of 1/4 inch thickness.
Place them in a large bowl. Add turmeric powder, sambar powder, red chili powder, salt and rice flour.
Add 1 teaspoon oil and toss well. Add 1-2 tablespoons water only if needed. Set aside. Heat 2 tablespoons oil in a cast iron skillet or flat pan. Add 1 teaspoon mustard seeds and a handful of curry leaves.
Once curry leaves turn crispy, place the spice tossed arbi roots as single layer. Fry in low flame until crispy and golden. Flip frequently and cook thoroughly from all sides.
Once completely cooked and crispy remove to a plate. Serve arbi fry immediately.