Pick the leaves off the basil. Blanch in boiling water for 5 seconds, drain, and puree with the vegetable oil.
Oil:
Crush the stalks along with the parsley, thyme, coriander seeds and the zest of the lemon.
Add to the oil and warm over a low heat.
Allow to infuse for 30 minutes.
Puree:
Sweat the onion in butter and then add the cauliflower florettes and the milk.
Cook until soft and then puree.
Fish:
Skin and bone the ocean trout as demonstrated.
Place the ocean trout in the warm oil. Make sure the oil is not hotter than 60 Celsius ( 140 Fahrenheit) and leave for 10 minutes or until the fish is cooked but firm.
To Serve:
Spoon the cauliflower puree between 4 plates.
Place a piece of ocean trout in the centre of each, top with the mesculin and sauce with basil oil.