Heat oven to 425. Line a rimmed large metal baking sheet with parchment paper. Toss the squash in enough avocado oil to lightly coat, spreading the squash in an even layer. Roast for 20 minutes, then flip and roast 10 minutes more. Push the squash to one side of the baking sheet, then carefully toss the kale on the baking sheet in enough avocado oil to lightly coat. Roast for 8 minutes or until the kale is starting to crisp. Remove the vegetables from the oven. Season with salt.
Meanwhile, in a medium-small pot, whisk the broth, pumpkin, wine and salt until well-combined. Bring to a boil, then slowly whisk in the polenta. Reduce the heat to low and gently simmer for 10 minutes, partially covered, stirring occasionally. Stir in 1/4 cup oat milk, then cook for another 10 minutes. Stir in the remaining 1/4 cup oat milk, then cook for 10 minutes more, or until the polenta is creamy, and the individual grains are tender. Stir in the nutritional yeast, lemon juice, and black pepper.
When the polenta has about 10 minutes left to cook, heat a medium-small pan over medium heat. Melt the butter, then cook the herbs over medium-low until sizzling and the butter is frothy, about 5 minutes. Add the red pepper flakes then cook one more minute. Fold the spiced butter and herbs into the cooked polenta, reserving about 1/2 teaspoon of butter in the pan to drizzle on top before serving. Add more salt to the polenta, if needed.
Spoon the polenta in a bowl, then top with the roasted kale and squash. Drizzle the vegetables with the remaining butter.
