In a medium pot, bring 3 cups of water to a high simmer. Slowly whisk in the polenta. Add 1 more cup of water and simmer for 15 minutes, stirring frequently. If your polenta is very thick, whisk in the remaining ½ cup of water. The polenta should be creamy.
Turn off the heat and whisk in the butter and sea salt. Cover and let stand for 5 minutes. Season to taste and serve hot.
Mushrooms
In a large cast-iron skillet, heat the oil over medium heat. Add about half of the mushrooms, salt, and pepper, and toss to coat. Let the mushrooms cook, without stirring, for 2 to 3 minutes. This will help them get a nice golden brown sear. Give the pan a good shake or two and continue cooking the mushrooms, stirring only occasionally, until soft and well-browned, 5 to 8 more minutes depending on the size of your mushrooms. Make sure all the water the mushrooms have released is cooked off so you get crispy mushrooms.
Remove the mushrooms from your pan and repeat with the other half of the mushrooms. Once all mushrooms are cooked, return them all to the pan.
Turn the heat to low and stir in the rice vinegar, tamari, and garlic. Turn off the heat and sprinkle with fresh herbs of choice.
Chimichurri
Add everything but the olive oil to a food processor and pulse until combined and the parsley is minced. Slowly add the olive oil to the food processor.
Serving
Serve the polenta hot, top with the mushrooms, then drizzle with chimichuri and serve!
Storage Instructions: Store these leftovers separately in an airtight container in the fridge for up to 4 days.
Reheating Instructions: Reheat over medium heat in a skillet with a small drizzle of oil to crisp the polenta again. If reheating from frozen, thaw overnight in the refrigerator and reheat gently in the skillet until warmed through. When you go to serve, take the chimichurri out of the fridge about 10 minutes before serving so the oil warms up.