Cut Karela into 3-inch pieces and then make a vertical slit into each to open the Karela piece. Stuff about ¼ teaspoon kosher salt in each Karela and line them up in a medium-sized pan.
Add 4 to 6 cups of water to the pan or until the Karela pieces are just submerged under water. Place the pan on stove top and cook on high heat until the water comes to a rolling boil. Lower the heat and cook for additional 5 mins. Turn the heat off. Drain out all the water.
Run cold water over the Karela. Squeeze out excess water from each piece by firmly pressing each piece between the palm of your hands. Open up each piece by flattening it and then remove and discard any big seeds that will be the middle portion pieces.
To a small bowl add jaggery and tamarind paste. Mix well. Add one to two tablespoons of water to thin it out. Dip the Karela piece one at a time coating both sides with the tamarind jaggery paste and keep them aside.
Next add besan, rice flour, turmeric, red chili powder, cumin powder, coriander powder, salt, garam masala, ground peanuts and cilantro to a bowl. Mix well.
Dip each piece of the Karela in the dry mixture, pressing down to coat both sides with the dry spice mix.
Heat oil in a medium nonstick frying pan over medium heat. Line up 7 to 8 pieces of Karela in the pan and gently press down. Cook for 3 to 4 minutes and then flip them over and cook the other side for additional 4 to 5 minutes.
Garnish with more cilantro and sesame seeds, Serve with hot Roti and Raita.