Heat the oil in a large frying pan over a high flame. Add the scallions and stir-fry for 30 seconds. Add the carrot, squash, and red pepper and stir-fry for one minute. Remove from heat and stir in the bean sprouts, snap peas, soy sauce, and teriyaki sauce. Taste and add more sauce if necessary.

Lay a spring roll wrapper on a work surface and spoon some of the vegetable mixture diagonally across the center. Roll one corner over the filling and flip the side of the wrapper over the top to enclose the filling. Continue to roll up, sealing with a little water. Repeat with the remaining wrappers and filling to make eight spring rolls.

Heat the oil for deep-frying in a large frying pan to 350 degrees Fahrenheit (180 degrees Celsius) – or until a cube of bread browns in 30 seconds. Add the spring rolls, in two batches, and cook until crisp and golden brown. Remove with a slotted spoon and drain on paper towel. Serve immediately.