Preheat the oven to 400 degrees. Place the squash, cut side down, on a parchment lined baking sheet and bake for 45 minutes.
While the squash roasts, place the quinoa and broth or water in a medium size pot. Bring to a boil, reduce to a simmer and cover for 15 minutes or until water is absorbed and quinoa is tender.
While quinoa is cooking, heat a thin layer of oil in a large saute pan over medium high heat and saute the mushrooms for 4 minutes. Add the garlic cloves and saute one more minute or until mushrooms are golden and tender.
Place the walnuts on a baking sheet in the preheated oven and toast for 10 minutes or until lightly golden.
Add the sautéed mushrooms, walnuts and leaves of the thyme into the quinoa and stir to combine.
Spoon the quinoa mixture generously into each halved squash, lightly pressing down to fit more mixture.
Return the squash to the oven and bake for 10 minutes or until warmed through. Remove and drizzle with Italian Salsa Verde.