First, cook the breakfast sausage in your cast iron pan over medium heat until it's well-done and nicely browned. Remove the cooked sausage from the pan with a slotted spoon, setting it aside. Be sure to leave about a quarter cup of the rendered fat in the skillet for the gravy.
Next, add the flour to the sausage drippings in the pan. Cook this mixture, stirring constantly, for about 5 to 10 minutes until it turns a light golden brown. This step is crucial for cooking out the raw flour taste and creating a rich, nutty flavor base for your gravy.
Once the flour mixture is toasted, slowly pour in the milk while whisking constantly to prevent any lumps from forming. Continue to cook, stirring often, until the gravy comes to a boil and thickens into a creamy, luscious sauce. Season it with salt and pepper to your liking.
While the gravy is simmering, you can prepare the other components. Split the English muffins and lightly toast them in a toaster until they are just beginning to turn golden. This creates a firm base for your pizza toppings.
In a separate non-stick skillet, scramble the eggs. For extra fluffy eggs, you can add a small splash of milk before whisking them. Cook them over medium-low heat until they are soft and just set, as they will cook a little more under the broiler.
Now for the fun part: assembling your breakfast pizzas. Turn your oven's broiler on high and arrange the toasted English muffin halves on a baking sheet. Spread a generous layer of the warm sawmill gravy over each muffin half.
Next, top the gravy with a portion of the scrambled eggs, followed by the cooked sausage crumbles. Finish by placing a slice of cheddar cheese over the top of each pizza. Place the baking sheet under the broiler for a few minutes until the cheese is completely melted and bubbly.