Preheat oven to 400°F (200°C).

Line a sheet pan with aluminum foil.

Place squash cut side down on prepared pan. Roast until tender, about 45 minutes.

Remove squash from oven and increase oven temperature to 450°F (232°C).

While roasting the squash, bring 2 cups of water to a boil. Stir in soaked barley and salt. Cook until barley is tender, about 45 minutes. Drain off any excess water. Keep warm.

In a large saute pan, heat oil then add the fennel and shallot. Cook until lightly browned, 5-7 minutes.

Add the garlic, coriander, thyme, and pepper. Cook until fragrant - less than a minute.

Remove from heat and add the parsley and half of the parmesan. Combine with the barley.

Scoop out the flesh of the roasted acorn squash, leaving about 1/8-inch thickness in the shell.

Gently fold the scooped squash flesh into the barley mixture, then fill the squash shells, mounded above the rim.

Sprinkle the remaining parmesan on top and bake until cheese has melted.

Drizzle with balsamic vinegar to taste.

**If you are using pearled barley, omit overnight soaking and cook for 20-25 minutes. Note that pearled barley is not a whole grain.