Preheat oven to 325 degrees. Slice baguette into 1-inch cubes. Spread in a single layer on a baking sheet. Bake for 20 - 25 minutes, stirring occasionally. Test for crunch and bake an addition 5-10 minutes if necessary.
Meanwhile, in a Dutch oven, brown sausage and remove to drain. Add mushrooms and allow to caramelize over medium heat for 8-10 minutes. Reserve with sausage.
Add butter and herb sprigs to pan over low heat; sauté for 5 minutes. Add onion, carrots, and celery to pan and sauté until tender, about 10 minutes.
Add chicken broth and bring to a boil. Remove from heat and remove herb sprigs. Gently fold in toasted bread cubes and cooked quinoa. Season with salt & pepper to taste.
Pour stuffing into a 2 quart buttered casserole or use to stuff a whole roasting chicken.
If serving as a casserole, bake stuffing at 350 degrees for 30 minutes. If stuffing a chicken, see recipe link in post.