Creating your own Cajun Shrimp and Crab Mac and Cheese may seem daunting, but it can be accomplished in just a few simple steps. Follow these instructions to achieve a delightful dish:

1. Cook the Pasta: In a large pot, bring salted water to a boil. Add the elbow macaroni and cook until al dente. Drain and set aside.
2. Season the Shrimp: In a bowl, toss the shrimp with Cajun seasoning until well coated.
3. Sauté Shrimp: In a large skillet over medium heat, melt 1 tablespoon of butter. Add the seasoned shrimp and cook for 3-4 minutes, until they turn pink and opaque. Remove shrimp from the skillet and set aside.
4. Make a Roux: In the same skillet, melt the remaining tablespoon of butter. Stir in the flour, cooking for about 1 minute until it’s bubbly and golden.
5. Add Milk: Gradually whisk in the milk, ensuring there are no lumps. Continue cooking, stirring frequently, until the mixture thickens, about 5-7 minutes.
6. Incorporate Cheeses: Reduce the heat to low and add cheddar, Monterey Jack, and Parmesan cheese. Stir until fully melted and smooth.
7. Flavor the Sauce: Add garlic powder, cayenne pepper, salt, and pepper to taste, stirring to combine.
8. Combine Pasta and Seafood: Gently fold the cooked macaroni, sautéed shrimp, and crab meat into the cheese sauce until everything is well coated.
9. Transfer to Baking Dish: Pour the mixture into a greased 9×13-inch baking dish, spreading it evenly.
10. Bake: Preheat your oven to 350°F (175°C). Bake for 15-20 minutes, until the top is golden and bubbly.
11. Garnish and Serve: Remove from the oven and let it cool slightly. Top with chopped green onions before serving.

By following these steps, you’ll create a mouthwatering dish that’s guaranteed to impress!