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.
Drizzle a little of the Chimichurri sauce over each of the roasted steaks.