Season the chicken and shrimp with 2 teaspoon of the Cajun seasoning and 1 teaspoon kosher salt. Add olive oil to a large nonstick skillet over medium heat. Cook the chicken first until the internal temperature is 160°F (approximately 4-5 minutes per side). Set aside while you cook the shrimp. Cook the shrimp in the same pan, adding a bit more olive oil if needed. Depending on the size of the shrimp, they will only take a couple of minutes per side over medium heat. Remove the shrimp and wipe the pan. Set the chicken and shrimp aside and slice the chicken right before adding it to the sauce.
1 Tablespoon plus 2 teaspoons Cajun seasoning, 1 teaspoon kosher salt, 2 chicken breasts, 1 lb shrimp, 2 Tablespoons olive oil
Fill a large pot with water and heat over high to bring to a boil while you make your sauce.
Heat a large nonstick pan over medium heat and add the butter until it melts. Next add the minced garlic and cook until fragrant without letting it develop any brown color - about 1-2 minutes. Whisk in the cream, the remaining 1 tablespoon of Cajun seasoning, and black pepper. Once it simmers, turn the heat to medium low, stirring often, and cook for 5 minutes.
6 Tablespoons unsalted butter, 3 garlic cloves, 1 ½ cups heavy cream, 1 teaspoon black pepper, 1 Tablespoon plus 2 teaspoons Cajun seasoning
Remove the pan from the heat until it stops simmering. Whisk in the grated Parmesan cheese and put it back on the stove on low heat, whisking constantly for 1 minute until the sauce is smooth. Cook for 2 more minutes then taste and add salt if needed. Turn the heat off and stir in the shrimp and sliced chicken.
1 ¾ cups Parmigiano Reggiano, Kosher salt
Add some salt to the pot of boiling water (about 2 tablespoons for every 6-8 quarts of water), and cook the pasta following the package directions until al dente. If using fresh homemade pasta, cook for 2 minutes. Right before the pasta is done, remove a cup of pasta water from the pot and set aside.
8 ounces fettuccine pasta
When the pasta is done, drain, and transfer the cooked pasta to the pan with the sauce. Stir thoroughly to coat the pasta. If the sauce is too thick, add a little of the reserved pasta water to thin - a tablespoon at a time. Garnish with green onions and serve!
4 green onions