If necessary, thaw or wash the cauliflower and cut into florets. Wash and quarter the peppers and remove the inner skins and seeds. Then cut into small pieces.
Halve the spring onions and rinse well. Cut off the dark green top pieces and only use the rest. Cut into larger rolls.
Thaw the peas. Peel and finely dice the onion and garlic or, if preferred, press the garlic through a press.