In a food processor or powerful blender, process the ginger, garlic, chilli and coriander (leaves and stems) to a fine paste. If using a Thermomix 10 seconds, speed 7.
Add the lime zest, juice, fish sauce, coconut milk and half the cashew nuts. Process until it forms a smooth sauce and put half the sauce in a small pot over a low heat to warm (don't let it boil). Taste and adjust the balance of flavours (it should be pretty good, but best to check). If using a Thermomix 20 seconds, speed 8. Then heat 5 minutes, temp 90, speed 2.
Now prepare and cook your vegetables.
Heat a little oil (I use coconut or macadamia nut oil) in a wok or large frypan over a high heat. Add the mushrooms and cook for one minute stirring constantly. Add the carrot, broccoli and cauliflower and stir for a minute then add the snow peas, capsicum and tofu.
Cook, stirring for another minute or so then take off the heat.
In a big mixing bowl combine the warmed sauce and vegetables (so the vegetables are covered in sauce).