Peel and dice the potatoes into small cubes, then boil in salted water for about 8-10 minutes until just tender. Drain and set aside.
Chop the mixed vegetables finely so they cook evenly and fit inside the pastry—aim for small, uniform pieces.
Lightly toast the cumin in a dry pan until fragrant, about 30 seconds, then add the chopped vegetables and sauté over medium heat until they soften slightly and start to smell aromatic, about 3-4 minutes.
In a large mixing bowl, gently mash the drained potatoes, leaving some texture, then fold in the sautéed vegetables, ground coriander, garam masala, and a squeeze of lemon juice. Mix well and taste—adjust salt or spices if needed.
Keep the spring roll wrappers covered with a damp cloth to prevent drying out. Lightly dust your work surface and roll out the wrappers if they’re thick, just to make them easier to fold.
Place a spoonful of filling onto one corner of a wrapper, then fold into a triangle or semi-circle, sealing the edges with a dab of water along the perimeter. Repeat with remaining wrappers and filling.
Heat the oil in a deep pan over medium-high heat until it reaches around 180°C (355°F). You can test by dropping a small piece of bread—if it sizzles immediately, it's ready.
Carefully lower a few samosas into the hot oil, frying in batches. Cook for about 4-5 minutes, turning occasionally, until they are golden brown and crispy, with a bubbling sound as they fry.
Use a slotted spoon to remove the cooked samosas and drain on paper towels. Let them rest for 2-3 minutes to finish crisping up, then serve warm with chutney or yogurt.
