Clean leeks: Remove tough ends, slice white and green parts into thin rounds, then chop. Place the chopped leeks into a medium bowl and cover with water. Allow to sit in water for about 5 minutes so grit falls to the bottom of the bowl. Remove leeks to a towel with a slotted spoon or your hands, then pat dry.
Preheat oven to 350 degrees.
Grease 3-quart baking dish with about 1 tbsp Earth Balance.
Melt remaining Earth Balance in a large saute pan over medium heat.
Add celery, Vidalia onion and leeks and saute until the vegetables are soft and fragrant, about 5 minutes. Allow to cool.
Place bread cubes into 3-quart, oven-safe baking dish, then add parsley, thyme, sage, salt and pepper and toss to combine.
Add cooled vegetables and vegetable stock and gently stir until ingredients are evenly distributed.
Cover baking dish with lid or foil and bake for about 30 minutes or until stuffing is slightly brown on top.
Note: If you’re taking this to someone’s house, complete steps 1-8, allow to cool enough to take with you, and when you arrive, place in your host’s oven until warmed through.