What is the primary vegetable served with Cauliflower Steak?

The primary vegetable that complements Cauliflower Steak is cauliflower puree. This choice highlights the focus on cauliflower in the dish, as the puree serves as both a flavorful base and a contrasting texture to the grilled or roasted cauliflower steak itself. Using cauliflower puree allows for a harmonious presentation and intensifies the dish's flavor profile, as it integrates the main ingredient in a different form.

In terms of the other options, while carrots, potatoes, and green beans are delicious vegetables that can accompany many meals, they do not serve to emphasize the theme of the Cauliflower Steak dish in the same way that cauliflower puree does. Instead, they would serve as side dishes without the specific focus on enhancing the flavor of the cauliflower itself.