Step 1

In a large pot, add the wild rice blend and 1 3/4 cups of the chicken broth and cook until the rice is tender, according to the package directions. If the mixture seems dry before the rice is fully cooked, add the extra broth, a little at a time.

Step 2

In a large bowl, add the cooked rice and fluff it lightly with a fork.

Step 3

Allow the rice to cool to room temperature, about 30 minutes.

Step 4

Preheat the oven to 425 degrees F.

Step 5

Line an 18x26-inch baking sheet with parchment paper.

Step 6

Lightly grease an 8-inch square baking dish.

Step 7

On the prepared baking sheet, add the squash, the onion wedges, the mushrooms, and 2 of the rosemary sprigs.

Step 8

Drizzle the veggie mixture with the balsamic vinegar, 2 tablespoons of the oil, and 3/4 teaspoon of the salt and toss to coat.

Step 9

Spread the veggie mixture out evenly in a single layer.

Step 10

Roast the veggie mixture until the squash is tender and browned, about 25-35 minutes.

Step 11

Allow the veggie mixture to cool to room temperature, about 20 minutes.

Step 12

Remove and discard the rosemary sprigs. Don't worry if some of the leaves remain.

Step 13

In a small saucepan over medium heat, add the heavy cream and the remaining rosemary sprig and cook, while stirring occasionally, until the cream just begins to bubble around the sides of the pan.

Step 14

Transfer the heavy cream mixture from the stovetop to a wire rack and let it stand until slightly cooled, about 15 minutes.

Step 15

Add the veggie mixture, 1/4 cup of the parmesan cheese, and the remaining salt to the rice and toss to combine.

Step 16

Evenly transfer the rice mixture to the prepared baking dish.

Step 17

Remove and discard the rosemary sprig from the heavy cream mixture.

Step 18

Evenly pour the heavy cream mixture over the top of the rice mixture.

Step 19

Evenly sprinkle the remaining parmesan cheese on top of the rice mixture.

Step 20

Evenly drizzle the remaining olive oil on top of the rice mixture.

Step 21

Bake the casserole until it is bubbly around the edges and the top is browned, about 30-35 minutes.

Step 22

Serve hot.