2 small acorn squash (about 1 1/2 pounds each), halved and seeded
2 teaspoons olive oil
Salt and pepper
3/4 cup pearl barley, rinsed and drained
1 onion, minced (about 1 cup)
1 fennel bulb, halved lengthwise, cored, and chopped fine
6 garlic cloves, minced
1 teaspoon minced fresh thyme or 34 teaspoon dried
1 teaspoon ground coriander
2 ounces Parmesan cheese, grated (abouti cup)
2 tablespoons minced fresh parsley
2 tablespoons pine nuts, toasted
1 tablespoon unsalted butter
4 teaspoons balsamic vinegar

Adjust the oven racks to the upper—middle and lower-middle positions and heat the oven to 400 degrees. Line a rimmed baking sheet with foil and lightly spray with vegetable oil spray.

Brush the cut sides of the squash with 1 teaspoon of the oil, season with salt and pepper, and lay them cut side down on the prepared baking sheet. Roast on the lower-middle rack until tender (the tip of a paring knife can be slipped into the flesh with no resistance), 45 to 55 minutes. Remove the squash from the oven and increase the oven tenperature to 450 degrees.

Meanwhile, bring 3 quarts water to a boil in a large saucepan. Stir in the barley annd ¼ teaspoon salt. Return to a boil, then reduce to a simmer and cook until the barley is tender, 20 to 25 minutes. Drain and set aside.

Wipe the saucepan dry and add the remaining 1 teaspoon oil, the onion, and fennel. Cover and cook over medium—low heat, stirring occasionally, until the vegetables are softened, 5 to 10 minutes. Stir in the garlic, thyme, and coriander, and cook until fragrant, about 30 seconds.

Off the heat, stir in the barley, 3/4 cup of the Parmesan, the parsley, pine nuts, and butter. Season with salt and pepper to taste.

Flip the roasted squash over and scoop out the flesh, leaving a 1/8—inch thickness of flesh in each shell. Gently fold the squash flesh into the barley mixture, then mound the mixture into the squash shells (abou 1 cup of filling per shell).

Sprinkle with the remaining ¼ cup Parmesan. Bake on the upper-middle rack until the cheese is melted, 5 to 10 minutes. Drizzle with the balsamic vinegar and serve. (The stuffed squash can be asembled through step 6, covered loosely with plastic wrap, and refrigerated for up t0 4 hours. Finish and bake as directed, increasing the baking time to 25 to 30 minutes.)