Spread cubed sourdough on a baking sheet and put into the oven for 10 minutes to dry out.
In a skillet, heat oil over medium-high heat, then brown sausage meat, breaking up with a spoon, until cooked through. Add celery and onion, and sauté until vegetables are softened. Stir in the garlic, sage, and thyme.
Put toasted bread cubes into a large bowl, and add sausage mixture, mixing until combined.
Add poultry stock, one-half cup at a time, combining until bread is moist but not soggy.
Add blueberries, combining well, then salt and pepper.
Use 1 tablespoon of butter to grease a 9”x 12” casserole dish, and transfer stuffing to the casserole.
Put the remaining butter in dabs on the top of the stuffing, and bake at 350° for 30 minutes.
Notes
This recipe can be made up to two days ahead and refrigerated, unbaked, until ready to use.If desired, add turkey drippings to the stuffing before baking.