Trim the thick stems and wash the swiss chard leaves a couple of times. Pat dry each leaf with paper towels. Fold each leaf into half with the stem vein running in the middle of the leaf. Carefully cut the thicker vein, while trying to keep the leaf still in one piece. Sometimes the leaves do split into two on the top, which is ok. The key is to trim thicker stem which makes rolling the leaves easy.
Mix gram flour, red chili powder, turmeric, tamarind pulp, jaggery and salt with some water. Make a smooth paste that is not too thick or thin. Add water slowly to get a good consistency that is slightly thinner than peanut butter.
Each roll can use 10-12 leaves. So depending on how many leaves you have, I would divide up the leaves into different piles, each having leaves that go from smallest to biggest leaf. I had about 24 leaves, of all different sizes so I decided to make 2 rolls.
Start with the biggest leaf, lay it upside down on a large cutting board. Apply about 2 to 3 teaspoons of the gram flour paste evenly to the leaf. After the first leaf has a thin layer of paste applied all over, take another leaf that is slightly smaller or same size as the first leaf. Put it on top of the first and apply some paste to the back of the second leaf. Repeat this process for the first 10-12 leaves, starting with the biggest leaf to the smaller ones. Then start rolling the stack of leaves starting from the narrow end. Roll as tightly as possible and folding any thin edges inward. Keep the roll aside.
Repeat the same process for the remaining leaves and make another tightly folded roll. Arrange the rolls in a lightly greased steamer rack.
Add 1 cup of water to the steamer pot and put on medium-high heat. Put the steamer rack with the rolls in them in the pot. Cook covered for 15 mins. Turn the heat off. Let the rolls cool down completely. Then cut each roll into ¼ inch thick slices.
Heat a skillet on medium high heat and grease with 1 tablespoon oil. Arrange the slices on the skillet. Sprinkle half of the sesame seeds on top. Cook for 4-5 mins on medium heat, spread remaining oil over them and then carefully flip over. Sprinkle remaining sesame seeds on top. Cook for another 4-5 mins or until the Vadi are golden brown and crispy.
Layered swiss chard spirals or Aloo Vadi can be optionally garnished with chopped cilantro and fresh grated coconut. Enjoy hot!