Cajun Shrimp Alfredo

Cook pasta according to package directions. Drain and set aside.

Cook the shrimp:
Toss together the shrimp and Cajun seasoning in a medium bowl to coat.
Add the oil to a large skillet over medium-high heat. Tilt to coat the skillet. Add the shrimp to the skillet and cook until opaque, about 2 minutes per side. Transfer the shrimp to a plate.

Make the sauce:
Add the onion, celery, and garlic to the skillet and cook, stirring often, until the onion is tender, about 3 minutes.
Add the chicken stock and stir to loosen the browned bits from the bottom of the skillet. Stir in the heavy cream, Parmesan, pepper, salt, and cayenne. Cook, stirring often, until thickened, 4 to 5 minutes.

Add the pasta and toss:
Add the cooked, drained pasta and toss to coat. Top with the shrimp and sprinkle with scallions. Serve immediately.