Prep the ingredients:
Cut the chicken into 1-inch pieces and season with salt, pepper, and garlic powder.
Thaw shrimp if frozen, pat them dry, and season them with salt and pepper.
Cook the chicken:
In a large skillet, heat olive oil and 1 tablespoon butter over medium-high heat.
Add the chicken pieces and cook until golden brown, about 5-7 minutes.
Remove the chicken from the skillet and set aside.
Cook the shrimp:
In the same skillet, add another tablespoon of butter and sauté the shrimp until they turn pink and opaque, about 2-3 minutes.
Remove shrimp from the skillet and set aside.
Make the Alfredo sauce:
In the same skillet, melt 3 tablespoons of butter over medium heat.
Add minced garlic and sauté for 30 seconds until fragrant.
Stir in heavy cream and cream cheese until smooth.
Gradually add the grated Parmesan cheese, whisking continuously to avoid clumps.
Add Cajun seasoning for a flavor boost if desired.
If the sauce is too thick, add a splash of pasta water until the desired consistency is reached.
Combine:
Return the cooked chicken and shrimp to the skillet.
Stir everything together to coat the proteins in the creamy Alfredo sauce.
Prepare the pasta:
Meanwhile, cook the pasta according to package instructions, drain, and set aside.
Serve:
Plate the fettuccine, top with the chicken and shrimp Alfredo mixture, and garnish with freshly grated Parmesan and parsley.