Southern Lobster and Shrimp Mac and Cheese

Bring a large pot of lightly salted water to a boil. Cook elbow macaroni and 1/2 cup dried onion in the boiling water, stirring occasionally, until macaroni is tender yet firm to the bite, about 8 minutes. Drain.

Place lobster and shrimp in a colander. Pour the cooked pasta and onions over shellfish; let drain.

Preheat the oven to 375 degrees F (190 degrees C).

Warm evaporated milk and cream slowly in a saucepan over medium-low heat. Whisk in flour. Whisk eggs together in a small bowl.

Cook sauce until small bubbles form. Add sauce very slowly, 1/4 cup at a time, to the bowl with the eggs, being careful not to cook and scramble the eggs. Slowly mix the egg-cream mixture back into the pan. Continue cooking on medium-low heat, stirring occasionally, until thick and smooth, 5 to 10 minutes.

Melt 1 stick of butter in the pot used to cook the pasta over medium heat. Add flour; cook until roux thickens and turns caramel in color, about 5 minutes. Stir in Cheddar cheese, Swiss cheese, and Monterey Jack cheese. Cook, stirring constantly, until mostly melted, about 4 minutes. Pour in the cream sauce and stir until smooth.

Stir pasta, lobster, and shrimp into the cheese and cream sauce to coat completely. Pour mac and cheese into a 9x11-inch baking dish.

Melt another stick of butter in the saucepan used to make the sauce. Add onion seasoning and herbes de Provence; stir. Add crackers. Cook and stir over medium heat until coating mixture is lightly toasted, about 5 minutes.

Cover mac and cheese with thin pats of butter. Top with the cracker coating.

Bake in the preheated oven until top is crispy and cheeses are melted, about 1 hour.