Preheat oven to 325° to 350° (use temperature turkey requires). In a large pot over medium-high heat, sauté onions and celery with butter until vegetables begin to brown, about 12 minutes. Stir in juniper, garlic, and pepper, and cook about 1 minute. Remove from heat and stir in croutons and 1/3 cup parsley. Combine broth and egg in a small bowl, then mix with croutons.
Spoon stuffing into a 9- by 13-in. dish. Cover with foil and bake until steaming, 30 minutes. Uncover and bake until golden, 15 minutes. Scatter with parsley.
*Find in the spice aisle.
Make ahead: Up to 1 day, make stuffing, put in casserole, cover, and chill. Bake about 1 hour before uncovering.
Note: Nutritional analysis is per 3/4-cup serving.