How to Make It
Heat the oven to 400°F. Heat a frying pan over medium-high heat, spray with nonstick cooking spray, and brown the cauliflower steaks on both sides. Transfer to a cookie sheet lined with parchment paper, sprinkle with the Parmesan, put in the oven, and bake for 12-15 minutes.
Use a stick blender to blend the garlic, capers, basil, mint, parsley, red wine vinegar, and mustard into a rough paste.
Serve the cauliflower alongside the sliced tomatoes and arugula.