Using a grater or food processor, grate the cauliflower until it resembles the consistency of rice.
Chop up the rest of the vegetables into stir fry sized chunks.
Heat the oil in a large frypan or wok.
First add the peppers, carrots, broccoli, garlic and onion and saute for 10 minutes or until soft, then add all the other vegetables.
Season to taste with salt and pepper. Add the stock and continue to cook, stirring continuously, until the vegetables are just tender.
Notes
You can speed things up by pre steaming some of the veggies that take longer to stir fry, like carrots or broccoli.I also like to add some mixed herbs to my rice.