In a small skillet melt butter over medium high heat. Add onion and celery and cook until softened and translucent, about 4-5 minutes. Add salt, seasoning and pepper and mix again to combine. Set aside.
In a large bowl add eggs and beat with a whisk. Add chicken broth and mix to combine. Gently fold in bread cubes and parsley. Add onion and celery mixture into the bowl and mix everything to fully combine.
Add mixture evenly into muffin pans, filling them up to make about 20-24 muffins.
Bake for 22-24 minutes or until crispy on top. Remove from oven and serve.