Step 1: Prepare the green onion pancake dough: In a large bowl, combine flour and salt. Gradually add hot water, mixing with chopsticks or a spoon until shaggy. Add cold water and knead for 5-7 minutes until smooth. Cover and let rest for 30 minutes.
Step 2: While the dough rests, make the samosa filling: Heat oil in a pan over medium heat. Add cumin seeds; let them splutter. Add chopped onion and sauté until golden brown, about 5-7 minutes.
Step 3: Add minced garlic and grated ginger, cook for 1 minute until fragrant. Stir in turmeric, garam masala, and red chili powder. Cook for another minute, stirring constantly.
Step 4: Add mashed potatoes and thawed peas to the pan. Mix well, breaking up any large potato chunks. Stir in amchur (if using) and chopped cilantro. Season with salt. Cook for 2-3 minutes, then remove from heat and let cool completely.
Step 5: Assemble the green onion pancakes: Divide the rested dough into 8-10 equal pieces. Roll each piece into a thin rectangle (approx. 8×4 inches). Brush lightly with oil, sprinkle generously with green onions, and add a pinch of salt.
Step 6: Roll the rectangle tightly from the long side into a log. Coil the log into a spiral shape, tucking the end underneath. Flatten each spiral with your palm, then roll out into a 6-7 inch circle. Repeat for all dough pieces.
Step 7: Fry the green onion pancakes: Heat a lightly oiled non-stick pan over medium heat. Cook each pancake for 2-3 minutes per side, until golden brown and cooked through. Stack and keep warm. These are your Green Onion Pancake Samosa Wrappers!
Step 8: Form the samosas: Take one Green Onion Pancake Samosa Wrapper. Place a spoonful of cooled samosa filling in the center. Fold the pancake into a triangular shape, sealing the edges firmly. You can use a tiny bit of water to help seal if needed.
Step 9: Fry the samosas: Heat about 1 inch of oil in a deep skillet or pot over medium heat. Carefully place Green Onion Pancake Samosa Wrappers into the hot oil, ensuring not to overcrowd the pan.
Step 10: Fry for 3-5 minutes on each side, or until golden brown and crispy. Remove with a slotted spoon and place on a wire rack lined with paper towels to drain excess oil. Serve hot with your favorite chutney or dipping sauce.