Place a large skillet over medium heat then add sausage. Cook sausage, crumbling until evenly browned and cooked through. Drain excess grease then set aside to cool.
In a large mixing bowl, beat the eggs together with salt and half-and-half. Add green onions and cooked sausage then stir to combine.
Cut the bread into 1" cubes then stir the bread cubes and shredded cheese into egg mixture.
Spread mixture into prepared baking dish, cover with aluminum foil and chill in the refrigerator for at least 8 hours, or overnight.
Preheat oven to 350 degrees and bake, covered, for 60 minutes. Remove foil and continue to bake until completely set, about an additional 15–20 minutes.
Notes
Save the sausage drippings to make homemade gravy! Drizzle it on top of the casserole for extra flavor and indulgence.