Place the wood ear mushrooms and vermicelli noodles in small bowls and cover both with hot water. Leave each to sit until the mushrooms expand and the noodles become white, around 5-10 minutes for each. Drain both and chop the mushrooms finely and the noodles into small lengths.

As the mushrooms and noodles are soaking, finely chop the shallots and peel and grate the carrot.

Mix together the ground pork, mushrooms, noodles, shallots, carrot, salt, pepper and sugar. Use your hands if necessary to mix well (they may not all completely stick together but that's fine). Divide the mixture into 12 relatively equal pieces.

Lay one spring roll wrapper on a clean surface with a corner pointing towards you. Have a small bowl of water ready next to you. Fold over the nearest corner of the wrapper inwards to almost the middle of the wrapper and then put one portion of the filling on top in a small log cross-wise near the folded edge.

Fold in both sides to just be covering the end of the log and so the folds formed are parallel with each other. Fold the first folded edge over the filling, making sure the sides stay folded in to avoid the filling from escaping, and keep rolling up until only a triangle is left. Try to avoid having much air inside as you roll.

Dampen the tip of your finger and moisten the edges of the remaining triangle of the wrapper then keep rolling so that the end of the wrapper sticks flat onto the roll. Repeat with the rest of the wrappers and filling.

Warm the oil in a skillet over a medium-high heat (you can either do a few in a smaller skillet at a time and cook more in a larger skillet - it will be quicker more at a time but probably easier to turn before they cook too much if cooking smaller batches). Add the rolls to the oil and cook for around 2-3 minutes on each side until they are golden all over. Remove from the skillet and drain on kitchen paper. Repeat to cook the rest of the rolls, topping up the oil as needed.