Begin by thoroughly draining the canned tuna to remove excess oil. In a large mixing bowl, combine the drained tuna, finely chopped water chestnuts, shredded carrots, and diced red onions. Season the mixture with salt and pepper to taste, stirring gently until well combined.

Set up your wrapping station with the bowl of filling, spring roll wrappers, and cheese strips within easy reach. Keep the wrappers covered with a slightly damp cloth to prevent them from drying out. Place one wrapper on your work surface in a diamond position.

Spoon about 2 tablespoons of the tuna mixture near the bottom corner of the wrapper. Place a strip of cheese on top of the filling. Fold the bottom corner up and over the filling, then fold both sides toward the center. Roll the wrapper upward, keeping it tight to prevent oil from seeping in while frying. Lightly wet the top corner with water and seal completely. Set aside and cover with a clean, dry kitchen towel. Repeat this process with the remaining wrappers and filling.

Heat oil in a deep pan or kawali to 350°F (175°C). To test if the oil is ready, drop a small piece of wrapper in – it should bubble gently and rise to the surface. Carefully place 4-5 lumpia in the hot oil, making sure not to crowd the pan. Fry for 3-4 minutes, turning occasionally, until they turn golden brown and crispy.

Remove the cooked lumpia using a spider strainer or slotted spoon and place them on a wire rack to drain excess oil. Never drain on paper towels as this will make them soggy. Let cool for a few minutes before serving with your preferred dipping sauce.

Remember to bring the oil back to temperature between batches and maintain the heat at 350°F for consistently crispy results. The entire recipe should take about 40 minutes from start to finish, including prep time.