Step 1: Prepare the Filling
Heat 1 tablespoon oil in a pan. Add mustard seeds and let them splutter. Add finely chopped green chilies, ginger, and curry leaves. Sauté for a few seconds. 

Step 2: Cook the Masala
Add mashed boiled potatoes and mix well. Add turmeric powder, red chili powder, garam masala, salt, and a little lemon juice. Mix everything properly and cook for 2–3 minutes. Turn off the heat and let it cool. Add chopped coriander leaves. 

Step 3: Prepare the Wrappers
Place a spring roll sheet on a flat surface. Add 2 tablespoons of potato filling in the center. 

Step 4: Roll the Spring Rolls
Fold the bottom edge over the filling, fold both sides inward, and roll tightly. Seal the edges using a flour-water paste. 

Step 5: Frying
Heat oil in a deep pan. Fry the rolls on medium heat until golden brown and crispy. Remove and place on tissue paper. 

Step 6: Serve
Serve hot with green chutney, tamarind chutney, or tomato ketchup.