Preheat the oven to 400 degrees. Grease a 9x13-inch baking dish with nonstick cooking spray.
In a large skillet over medium high heat, cook the sausage until no longer pink. With a slotted spoon, remove the sausage to the prepared pan and spread it evenly in the pan.
Add the potato, onion, and mushrooms to the skillet and cook until the onion is clear, the potato is tender, and the mushrooms have browned. Season to taste with salt and pepper. Distribute these vegetables over the sausage in the pan. Strew the broccoli and tomatoes evenly throughout the pan. Top with the cheese, if using.
In a large mixing bowl, beat the eggs and whisk in the Dijon mustard. Pour this mixture over the vegetables and meat in the pan.
Sprinkle the olives atop the eggs, and bake for 25 minutes or until set. Serve hot or warm.
Notes
Nutritional values are approximate and are based on 1/10 of the recipe. Refrigerate leftovers promptly and use within 4 days.