Start by browning the sausage in a skillet over medium heat. Break it up as it cooks, allowing it to brown evenly. Once fully cooked, drain off any excess fat and let it cool slightly.
Preheat your oven to 375 degrees Fahrenheit. Press one pie crust into a pie plate, either deep-dish or standard. For an extra flaky crust, prick the bottom lightly with a fork and bake it for a few minutes before adding the filling.
Spread the cooked sausage evenly over the crust, followed by a generous layer of shredded Monterey Jack cheese. If you are using green onions, scatter them over the cheese.
In a separate bowl, whisk together the eggs, half-and-half, and seasonings until smooth. If you are using the dry mustard or hot sauce, add it here. Pour the custard gently over the sausage and cheese, allowing it to settle naturally.
If you like a top crust, place it carefully over the filling, crimp the edges, and cut a few small slits to allow steam to escape. If you prefer an open-faced version, you can skip the top crust and slightly reduce the baking time.
Bake until the crust is golden and the center is set, usually between 35 and 45 minutes. If the edges brown too quickly, cover them lightly with foil. Once done, let the pie rest for 10 to 15 minutes before slicing.
