Heat one tablespoon of the vegetable oil in a wok and sauté the pak choi for one minute. Add the garlic and cook for another minute. Add the soy sauce and stir well.
Heat the oil in a deep, heavy-bottom saucepan. It is ready when a breadcrumb sizzles gently in it. (CAUTION: hot oil can be dangerous; do not leave unattended.) Deep fry the shallots in the oil until golden. Remove with a slotted spoon and drain on kitchen paper.
To serve, spoon the pak choi onto a plate and sprinkle over the crispy shallots and cashew nuts.