Sauté the Butternut Squash: In a medium-sized pot, melt the butter over medium-high heat. Add the grated butternut squash and cook, stirring occasionally, until it turns golden and tender, about 5 minutes. Transfer the squash to a separate bowl and set aside.
Prepare the Polenta Base: Return the pot to the stove and reduce the heat to medium. Pour in 6 cups of water (or broth, if you prefer) and stir in 1 ¼ teaspoons of kosher salt and the bay leaf. Once the liquid begins to simmer, gradually whisk in the polenta. Add the sautéed squash to the mixture and stir continuously to prevent clumping. Continue stirring until the polenta thickens and stays suspended without sinking to the bottom of the pot, about 5–10 minutes.
Simmer the Polenta: Reduce the heat to low, cover the pot, and let the polenta simmer gently. Stir it occasionally to ensure it doesn’t stick, and cook for 15–30 minutes, depending on the grind of the polenta, until it’s fully tender.
Fry the Sage Leaves: While the polenta is simmering, heat 1 tablespoon of olive oil in a small skillet over medium heat. Add the sage leaves in small batches to avoid overcrowding the pan. Fry them for 1–2 minutes, or until they’re crisp. Remove the leaves with a slotted spoon and place them on a plate lined with paper towels. Sprinkle the fried sage leaves with ½ teaspoon of salt.
Finish the Polenta: When the polenta is ready, remove the bay leaf. Stir in the grated Parmigiano-Reggiano cheese, the remaining 3 tablespoons of olive oil, and a generous amount of freshly ground black pepper to enhance the flavor.
Serve the Dish: Spoon the creamy polenta into serving bowls. Top each portion with dollops of fresh ricotta, the crispy sage leaves, and a final sprinkle of black pepper. Serve immediately while warm.