Place the dried shiitake mushrooms in a bowl, add warm water to cover and leave to soak for 30 minutes or until soft.
While the mushrooms are soaking, cut the bean curd into slices about 0.5cm x 4cm x 5cm/½in x 1½in x 2in.
Place the bean curd pieces on a sheet or two of kitchen paper, cover with another piece of kitchen paper and pat them dry.
Remove the mushrooms from the water and cut off the hard stems. Discard the stems and return the caps to the soaking liquid until needed.
Heat the oil in a wok or deep-fat fryer over a medium-high heat; it should be about 5cm/2in deep in the centre of the wok if you are using one. (CAUTION: hot oil can be dangerous. Don't leave unattended.)
When the oil begins to shimmer, add the bean curd pieces and fry them until golden-brown on both sides - this should take about 5-7 minutes.
Remove the bean curd with a slotted spoon and leave to drain on a plate lined with kitchen paper. Very carefully drain off all but two tablespoons of the oil from the wok.
For the sauce, mix the cornflour with the one tablespoon of vegetable stock in a small bowl.
In a separate bowl, combine the light and dark soy sauces, sugar, 'oyster' or mushroom sauce, and the remaining vegetable stock and stir to mix.
Place the wok or large frying pan back on the hob, set over a high heat. When the oil is hot, add the garlic and stir-fry for 30 seconds.
Remove the mushrooms from their liquid, squeeze out any excess liquid and add the mushrooms to the garlic. Stir fry for 30 seconds.
Stir in the bean curd and pour over sauce mixture. Cover, turn the heat to low and simmer very gently for 7-8 minutes.
Add the peas. Simmer, covered, for a further two minutes.
Remove the lid and take the wok off the heat. Stir the cornflour mixture and pour it into the wok. Return to the heat, stir gently and cook, covered, on a low heat until the sauce has thickened. Add the sesame oil and stir.
Serve at once.
