01 -
Bring a large pot of generously salted water to a boil. Add the spaghetti and cook until al dente according to package directions, usually 8-10 minutes. Before draining, scoop out 1 cup of the pasta water and set aside. Drain the pasta.
02 -
While the pasta cooks, chop the red and yellow bell peppers, onion, and celery into small, even pieces. Mince the garlic cloves.
03 -
In a large, deep skillet or pan, melt the butter over medium heat. Add the chopped bell peppers, onion, and celery. Sauté until the vegetables begin to soften, about 5-6 minutes. Sprinkle in 1 tablespoon of Cajun seasoning and add the chopped garlic. Continue cooking for another minute until fragrant.
04 -
Sprinkle the flour over the sautéed vegetables and stir continuously for 1-2 minutes to cook out the raw flour taste. This creates a roux that will thicken your sauce.
05 -
Slowly pour in the reserved pasta water while stirring constantly to prevent lumps. Then gradually add the heavy cream, continuing to stir. Bring the mixture to a gentle simmer and add the grated parmesan cheese, black pepper, and garlic powder. Stir until the cheese is melted and the sauce is smooth and creamy.
06 -
In a separate skillet, melt a bit more butter over medium-high heat. Season the shrimp with the remaining tablespoon of Cajun seasoning and add them to the hot skillet. Cook for about 2 minutes per side until they turn pink and opaque. Be careful not to overcook them.
07 -
Add the cooked shrimp to the creamy sauce. Gently fold in the lump crabmeat, being careful not to break up the chunks too much. Let everything heat through for just a minute or two.
08 -
Add the cooked spaghetti to the sauce and toss everything together until the pasta is well coated. If the sauce seems too thick, add a splash more pasta water to loosen it up. Taste and adjust seasonings if needed.
09 -
Divide the pasta among four plates or bowls, making sure to evenly distribute the seafood. Garnish with additional grated parmesan and fresh herbs if desired. Serve immediately while hot.