For the gravy: Heat the butter in a saucepan over medium heat. Brown the sausage breaking it up into smaller pieces as it cooks. Stir in the flour and cook while stirring for 1 minute. Whisk in the milk and parsley bring to a simmer until it starts to become thick and smooth. Season with salt and pepper to taste. Cover with a lid and set aside.
Heat a nonstick pan on medium heat. Add the butter, eggs, and tomato. Move the eggs using circular motions with a spatula or wooden spoon to fluff up and cook, (move the pan on and off the heat as needed to prevent the eggs from cooking too quickly and overcooking or drying out). Remove the pan from the heat while the eggs are still moist. Season with salt and pepper to taste.
Place the eggs on the toast, spoon the gravy over top. Season with salt and pepper. Serve with blueberries. Garnish with chives.