Tuna Spaghetti Pie

Ingredients

• 4 ounces uncooked spaghetti, broken into 2-inch pieces
• 1/4 cup grated Parmesan cheese
• 1 large egg, lightly beaten
• 1 teaspoon butter
• 1 garlic clove, minced
• 1/4 teaspoon salt
• 1/8 teaspoon pepper
• 1 tablespoon finely chopped onion
• 1 teaspoon butter, melted
• 1 tablespoon all-purpose flour
• 1/2 teaspoon salt
• 1/4 teaspoon celery salt
• 1/4 teaspoon garlic and herb seasoning
• 1/8 teaspoon pepper
• 1/4 cup milk
• 1/4 cup sour cream
• 1 large egg, lightly beaten
• 1 can (6 ounces) tuna, drained and flaked
• 1/4 cup grated Parmesan cheese, divided
• 1 small tomato, thinly sliced
• Minced fresh parsley