Whisk the olive oil together with the red wine vinegar, lime juice and Chimichurri. Reserve ⅓ cup to later serve with the cooked cauliflower, and keep the rest as a marinade.
Preheat the oven to 200°C.
To prepare the cauliflower, carefully cut away the leaves and trim the stalk. Cut 2 thick cauliflower ‘steaks’ (3-4cm each), starting at the top centre and slicing down through the stem. Save the sides and loose florets for another use.
Use a pastry brush to baste both sides of the steaks with the marinade and set them aside on a baking tray for at least 10 minutes for the flavours to develop.
On a greased baking tray, sprinkle the cauliflower with salt and slide them into the oven. Roast for approximately 20 minutes on each side or until they are beginning to turn golden.