Step 1

Place sausage in medium saucepan over medium-high heat. Cook sausage, breaking apart with wooden spoon, until browned and cooked through. Using a slotted spoon, transfer sausage to a plate, leaving drippings in pan. If less than 3 tablespoons of drippings remain, melt enough butter in pan to equal about 3 tablespoons.

Step 2

Whisk flour into sausage drippings and cook, stirring constantly, until mixture turns light brown, about 1 minute. Slowly whisk in milk and bring to a boil. Reduce to a simmer and cook until slightly thickened, about 4 minutes, stirring occasionally.

Step 3

Stir in sausage, sage (if using), and crushed red pepper (if using). Remove from heat and season with salt and pepper to taste. Use immediately.