In a large pot of boiling salted water, cook pasta according to package instructions; drain well.
Melt butter in a saucepan over medium heat. Add garlic and onions. Cook stirring frequently, until fragrant, about 1-2 minutes.
Add in bell peppers and tomatoes. Saute for a minute or two.
Add in cajun seasoning and Italian seasoning. Stir for a few seconds, be sure to not let the spices burn.
Gradually whisk in heavy cream and lemon zest. Cook, whisking constantly until incorporated, about 1-2 minutes. Stir in Parmesan until slightly thickened, about 1-2 minutes. If the mixture is too thick, add more heavy cream as needed; season with salt and pepper, to taste.
Stir in pasta and gently toss to combine.
Serve immediately. You can add any protein of your choice to this, I tend to add chicken or shrimp to it depending on what I have on hand. It tastes great on its own as well. It tastes even better the next day! Enjoy!
Notes
You can add chicken or shrimp to this dish if you like as well. I just marinate my protein of choice for a bit to elevate the flavors even more.