Cook the fettuccine pasta in a pot of salted boiling water according to the package instructions. Drain and set aside.
In a large skillet over medium-high heat, add the olive oil. Once heated, add diced chicken breast and season with Cajun seasoning, salt, and pepper. Sauté until the chicken is cooked through and browned, about 5-7 minutes. Remove chicken from the skillet and set aside.
In the same skillet, add the diced onion and bell pepper. Sauté for about 3-4 minutes until softened. Add minced garlic and cook for an additional minute until fragrant.
Pour in the chicken broth and bring to a simmer. Let it reduce slightly for about 3-4 minutes.
Stir in the heavy cream and let it cook for an additional 2-3 minutes, stirring occasionally until the sauce thickens.
Add the halved cherry tomatoes and frozen peas, letting them cook in the sauce for another 2-3 minutes.
Return the cooked chicken to the skillet and stir to combine everything.
Add the cooked fettuccine to the skillet, tossing everything together to coat the pasta in the creamy sauce.
Stir in the grated Parmesan cheese, allowing it to melt into the sauce. Check and adjust seasoning if necessary.
Remove from heat and let the pasta sit for a minute to thicken further.
Notes
Serve in deep bowls, garnished with parsley and extra Parmesan cheese.