Tuna stuffed shells

Ingredients

• 18 jumbo pasta shells
• 1 can (6 oz) light tuna in oil, well drained
• 1 cup fresh white bread crumbs
• 1/4 cup finely chopped onion
• 1 large egg
• 1/4 cup minced fresh parsley
• 1 teaspoon fresh lemon juice
• 1 can (103/4 oz) condensed cream of celery soup
• 1/2 cup milk
• 2 tablespoons grated Parmesan cheese
• Paprika (optional)