In a large bowl, combine ground pork, chopped shrimp, grated carrot, bean sprouts, soaked wood ear mushrooms, and mung bean vermicelli. Mix well to evenly distribute the ingredients, ensuring a balanced texture for the filling.

Add minced garlic, shallots, beaten egg, fish sauce, sugar, and black pepper to the mixture. Stir thoroughly until the filling becomes well incorporated. Adjust seasoning to taste, ensuring a balance of savoury and slightly sweet flavours.

Prepare a clean surface for rolling. If using rice paper, lightly dampen each sheet with water to make it pliable. Place about 1-2 tablespoons of filling near the bottom edge of the wrapper, shaping it into a compact log.

Begin rolling by folding the bottom edge over the filling, then fold in the sides to secure. Roll tightly but gently, ensuring there are no gaps or tears in the wrapper. Repeat until all filling is used.

Heat a deep pan or wok with enough vegetable oil to submerge the rolls. Bring the oil to 180°C (350°F). Test the temperature by dipping the edge of a spring roll; it should sizzle immediately.

Fry the spring rolls in small batches to avoid overcrowding. Turn them occasionally for even cooking, frying until golden brown and crispy, about 5-7 minutes per batch. Transfer to a plate lined with paper towels to drain excess oil.

Prepare the dipping sauce (nuoc cham) by mixing 2 tablespoons of fish sauce, 2 tablespoons of lime juice, 1 tablespoon of sugar, 2 tablespoons of water, minced garlic, and chopped chili. Adjust the flavours to your liking.

Serve the chả giò hot with fresh lettuce leaves, herbs, and dipping sauce on the side. To enjoy traditionally, wrap each spring roll in a lettuce leaf with herbs before dipping into the sauce. The combination of crispy rolls, fresh greens, and tangy sauce makes for an unforgettable experience.