Remove the casings from the sausages. Heat 1 tablespoon of the olive oil in a skillet over medium-high heat and add the sausage meat. Cook, breaking up the meat into small pieces, until browned and cooked through, about 5 minutes. Drain on a paper towel lined plate and set aside to cool while you cook the vegetables. Wipe out any excess fat from the pan with paper towels.
Heat 1 tablespoon of oil in the same skillet over medium-high heat. Add the carrots, celery, and onion. Season with salt and pepper and add the sage. Cook until the vegetables are soft, about 10 minutes. Set aside to cool a bit.
Crumble the corn muffins into a large bowl. Put in the cooled sausage and vegetables. Add the eggs and 1/4 cup chicken stock. Using your hands, mix well adding more stock if the stuffing is too dry. Spray a 2-quart oven-proof baking dish with cooking spray. Put the stuffing into the dish and bake for 45 minutes to 1 hour, or until the top is browned and crispy.