Bring a large pot of water to a rolling boil.
Heat oven to 400 degrees.
Spray your casserole dish with cooking spray.
Trim the ends of the zucchini and halve them lengthwise.
Remove the seeds with a spoon or melon baller.
Boil the zucchini for 2 minutes and remove to the prepared baking dish.
Bake the zucchini for 15 minutes in the 400 degree oven.
Meanwhile, brown the sausage. Add the celery and onion and cook another 5 minutes over medium heat.
Add the seasonings and eggs to the sausage mixture and cook until eggs are just done.
When the zucchini is ready, take them out of the oven and carefully spoon the egg mixture into the zucchini boats.
Sprinkle with cheese and carefully return to the 400 degree oven. REMEMBER this pan is very hot!
Bake for 5 minutes or until cheese is melted.
Remove from the oven and sprinkle with green onions and tomatoes.