Recipe courtesy The With or Without {Meat} Cookbook by Jackie Newgent. I adapted it a bit based on the ingredients we had on hand. I used thyme, button mushrooms, and shelled pistachio nuts. I also used kosher salt and left out the hot pepper flakes. (Yes, I am wimpy!)
Ingredients
2 (1-inch-thick) whole slices from a medium head cauliflower (about 6 ounces per slice)
{With Meat} Add 4 ounces crumbled, uncooked ground turkey and a pinch of sea salt along with the mushrooms in step 2.
Instructions
Preheat the oven to 425°F. Brush the cauliflower "steaks" with 1½ teaspoons oil and arrange on a baking sheet. (We lined our baking sheet with parchment paper.) Roast until lightly caramelized and the cauliflower florets are cooked through, about 20 minutes. Gently flip over each "steak," sprinkle with ½ teaspoon minced rosemary, ⅛ teaspoon pepper, and the salt, and roast until well caramelized and the cauliflower stems are cooked through, about 12 minutes. Adjust seasoning.
Meanwhile, heat the remaining 1 teaspoon oil in a small saucepan over medium heat. Add the mushrooms and the remaining ½ teaspoon rosemary and ⅛ teaspoon pepper, and saute until the mushrooms are softened, about 5 minutes. Add the marinara sauce, broth, and hot pepper flakes, and bring to a boil over medium-high heat. Reduce heat to low and simmer, covered, until desired consistency, about 8 minutes. Adjust seasoning.