In a bowl, combine the leftover dressing or stuffing with 1 egg. Stir that in & then pour in the broth/stock. Mix it all together and while you are mixing, mash the dressing up to get a consistent texture. I start off with 1/4 cup and then add more as needed. I usually end up adding about 1/2 cup for my own personal dressing to thin it down enough to make a ‘waffle batter’