In a large non-stick skillet, add 1 TBS cooking oil and brown sausage until no longer pink.
Sprinkle flour over meat, stir and cook for 1 minute.
Gradually stir in 1 cup of milk. (If needed you can 1/4 cup more milk.) The mixture needs to be thick.
Mix in salt, pepper, and sage to your taste. Turn off burner and allow to rest.
Preheat oven to 350 degrees. Line a baking sheet with parchment paper.
Separate each biscuit in halves (top & bottom).
Place 2 TBS of thickened gravy mixture on bottom half of biscuit (in the center). Place top half of biscuit on top of the mixture. Seal edges completely so they won't pull apart.
Brush egg wash on top of each biscuit.
Bake for 12-15 minutes. Enjoy.