Preheat oven to 350º.
Peel onion. Cut large onions in half, across grain. Place in large kettle with 1” of salt water. Cover and bring to boil. Simmer 10 minutes or until onions are almost tender. Drain. Cut a 1/2 “ slice from the tops of whole onions. Scoop out centers, leaving a 1/2 “ shell. Drain well. Chop scooped out portions. Reserve 1/3 c. Sauté sausage until browned and crumbly. Fold in bread crumbs, parsley and reserved chopped onion. Season to taste. Sprinkle onion shells lightly with salt. Spoon in sausage mixture. Bake for 30-35 minutes.
1 package -6 oz- bread stuffing mix
1 1/2 c water
1/4 c melted butter
Combine stuffing mix with water and butter. Mix well and stuff onions.
Spinach and cheese stuffing:
1 package -10 oz - frozen spinach,cooked according to directions
1 - 3 oz package of cream cheese, softened
6 Tbsp grated Parmesan cheese
Combine drained spinach, cream cheese, 4 Tbsp Parmesan cheese and reserved onion. Season to taste. Salt onion shells, fill with spinach mix and sprinkle with remaining cheese. Bake as above.