Preheat oven to 425 degrees
Whisk together marinade ingredients. Set aside.
Cut cauliflower through head and stalk into 3/4 to 1-inch thick slices. Brush both sides with marinade. Arrange steaks in a single layer in a shallow baking dish.
Bake for 20 minutes, then flip steaks. Bake until the stalk portion is fork tender, approximately another 15 to 20 minutes. Serve with chimichurri sauce.