
Preheat oven to 375°F (190°C).

In a skillet, cook sausage and onion over medium heat until browned. Drain any excess grease.

Spread sausage mixture evenly into the unbaked pie shell.

Sprinkle shredded cheese over the sausage.

In a bowl, whisk together eggs, milk, flour, salt, pepper, and oregano.

Pour egg mixture over the cheese and sausage in the pie shell.

Bake for 30–35 minutes, or until the center is set and the top is lightly golden.

Let cool for 5–10 minutes before slicing.