Step 1

Position a rack in the middle of the oven and preheat to 425 degrees.

Step 2

On a large sheet pan, toss the squash with 1 tablespoon of the oil and 1/4 teaspoon of salt. Roast for 25 to 30 minutes, or until tender and lightly browned in spots, tossing once at the midway point.

Step 3

While the squash is roasting, in a small pot over medium-high heat, bring the broth to a boil. Reduce the heat to its lowest setting, cover and keep hot while you cook the farro.

Step 4

In a large, heavy saucepan over medium heat, heat the remaining 2 tablespoons of oil until shimmering. Add the onion and cook, stirring occasionally, until softened but not browned, about 3 minutes. Add the sage, the remaining 1/4 teaspoon of salt and the pepper and cook, stirring, for 1 minute more. Add the farro and cook, stirring frequently, until coated in the oil and toasted, about 3 minutes.

Step 5

Add the wine and increase the heat to high. Cook until the wine is mostly absorbed/evaporated, about 2 minutes. Ladle enough broth into the pot to just cover the farro. Lower the heat so the broth is at a simmer and cook, stirring occasionally, until the liquid is mostly absorbed, about 5 minutes.

Step 6

Continue to add more broth, a ladle or two at a time, ensuring the liquid is gently simmering and letting it get absorbed by the farro after each addition, until the farro is tender but still has a nice chew to it and its liquid is saucy, about 35 minutes. (You may not need all of the stock.)

Step 7

Stir in the squash and butter, if using, and cook until the squash is warmed through and the butter is melted, about 1 minute. Stir in all but 2 tablespoons of the cheese. Add a little more stock or water if needed to maintain a thick, saucy texture.

Step 8

Divide among shallow bowls, garnish with the remaining cheese and parsley, and serve.