Mix together eggs, stock, vegetable oil, garlic salt, onion, pepper and thyme. Add in the matzo meal. Cover and allow to sit in the fridge for an hour.
Bring a large saucepan of lightly salted water to a simmer. Roll the matzo mixture into balls and set on a greased plate. When finished, gently drop the balls into the water, cover then simmer until cooked through, about 20 minutes.
Gently remove matzo balls from water and set aside.
In a large saucepan combine chicken stock, carrots and celery. Simmer until soft then add matzo balls. Serve sprinkled with the green onions.