Ingredients

• 4 tablespoons extra-virgin olive oil
• Kosher salt
• 1 pound button or cremini mushrooms (see note)
• Freshly ground black pepper
• 1 large head cauliflower (about 2 pounds)
• 1 large shallot
• 2 sprigs fresh rosemary
• 4 ounces Parmesan or pecorino cheese (1 cup grated) 2 tablespoons unsalted butter, or more to taste

Directions

• 1. Add 2 tablespoons olive oil to a large skillet over medium-low heat. In a large pot, bring 2 cups water and a big pinch of salt to a boil over high heat. Trim and slice the mushrooms. Add them to the skillet as you work.
• 2. Sprinkle the mushrooms with salt and pepper and increase the heat to medium. Cook, stirring occasionally, until tender and lightly browned, 12 to 15 minutes. Meanwhile, trim and halve the cauliflower. With the flat side on the cutting board, chop each half into small bits. Add the cauliflower to the pot of water as you work.
• 3. Bring the cauliflower to a boil, then lower the heat so the water bubbles steadily. Cook, stirring occasionally, until the cauliflower is very tender and the liquid thickens, 10 to 12 minutes. If the mixture becomes too dry and sticks, add more water ¼ cup at a time. Meanwhile, trim, peel and slice the shallot. Strip the leaves from 2 rosemary sprigs and chop.
• 4. When the mushrooms are lightly browned, add 2 tablespoons olive oil and the shallot and rosemary. Cook, stirring, until fragrant, about 2 minutes. Remove from the heat. Grate 1 cup Parmesan.
• 5. When the cauliflower breaks down and looks like porridge, remove from the heat. Use a potato masher or immersion blender to purée it in the pot. Add 2 tablespoons butter and the Parmesan and return it to medium-low heat. Cook, stirring and adding water if necessary to make the cauliflower steamy and loose enough to drop from a spoon like polenta. (If the mixture is too soupy, raise the heat and let some liquid bubble away for a couple minutes.) Taste and add more butter or salt if you like; keep warm.
• 6. Return the mushrooms to medium heat until they sizzle. Spoon the cauliflower “polenta” into bowls, top with the mushrooms and serve.
• Variations
• Chianti Cauliflower “Polenta” with Mushrooms: Magenta polenta! Instead of using water to cook the cauliflower in Steps 1 and 3, substitute Chianti or another fruity red wine.
• Cauliflower “Polenta” with Zucchini: Instead of the mushrooms, trim 1 pound zucchini; slice crosswise into thin coins. Use ¼ cup chopped fresh parsley instead of the rosemary if you like. Cook and season the vegetables as you would the mushrooms.
• Mashed Potatoes with Mushrooms or Zucchini: This works with either the mushrooms in the main recipe or the previous variation. Substitute peeled baking potatoes, like russets, for the cauliflower. After cooking, mash by hand with a fork or potato masher—don’t use an immersion blender or they will get gummy. They may need 10 minutes more cooking time, depending on how small you chop them.
• Button vs. Cremini Mushrooms
• The second are darker, slightly firmer—and usually more expensive—than the first. So what’s the difference between common button mushrooms and increasingly common cremini (which are in fact baby portobellos)? They’re interchangeable in recipes, though cremini usually don’t release quite as much liquid during cooking, so the pan might dry out more quickly. For a more robust flavor and appearance, go the cremini route; for milder mushroom taste and a more supple texture, choose button mushrooms. Both have edible stems, so all you need to do is trim off the toughest bits at the bottom.

Photos