01 -
Preheat the oven to 350°F (177°C). Lightly grease a 9×13-inch baking dish with butter or nonstick spray.
02 -
Melt butter in a large skillet over medium heat. Add diced onion and breakfast sausage; cook, stirring occasionally, until sausage is browned and onion is translucent. Drain any excess fat.
03 -
Arrange biscuit dough pieces evenly across the bottom of the prepared baking dish.
04 -
Spread the cooked sausage and onion mixture evenly over the biscuit pieces.
05 -
In a mixing bowl, whisk together eggs, whole milk, and dried oregano until well-combined. Pour the egg mixture evenly over the sausage layer.
06 -
Sprinkle shredded cheddar cheese evenly over the top, then drizzle with prepared country gravy.
07 -
Bake in the preheated oven for 30 to 40 minutes, or until the top is golden brown and the casserole is set in the center.
08 -
Allow to cool slightly before slicing and serving warm.