Preheat the oven to 375 degrees F (190 degrees C)
Set an ovenproof skillet over medium-high heat and add sausage, cooking and crumbling with a wooden spoon until browned, about 5 minutes
Add white parts of the onions and cook for 1 minute
Sprinkle flour evenly over sausage and cook, stirring constantly for 2 minutes
Add milk and cook, stirring constantly until well blended
Bring mixture to a simmer and cook until thickened, about 5 minutes
Stir in remaining green onions and hot sauce and turn off heat
Separate 6 biscuits into 2 or 3 layers and shingle biscuit dough over sausage mixture
Brush a thin layer of egg evenly over biscuits and sprinkle evenly with everything seasoning
Bake in the preheated oven until biscuits are golden brown and cooked through, 18 to 20 minutes
