In a large bowl, toss together seafood, seasoning salt and lemon juice.
In a large skillet, heat oil over medium heat. Par-cook seafood for three to five minutes. Set aside in a small dish.
Fill a four litre pot halfway with water and bring to a boil over medium-high heat.
Add onion, celery, bell pepper and pasta and cook until al dente, about eight to ten minutes. Drain in a colander and transfer to a large bowl.
Add butter and two cups (500 mL) of the white cheddar to the bowl and mix to melt.
Add evaporated milk and half of the cream and mix. Add eggs and mix well.
Add remaining cheddar, Parmigiano-Reggiano and season to taste with salt and pepper. Add sour cream and mix well.
Divide pasta into ovenproof bowls or ramekins. Divide and place seafood over pasta and then cover with Gruyere cheese. Bake for about 20 minutes or until cheese is melted and oozing. Drizzle with garlic oil (optional) and serve at once with crusty toasted baguettes.