Cook pasta until al dente. Toss in olive oil and season with salt and pepper.
Heat oven to 375 degrees.
Melt butter in a large sauté pan over medium heat.
Add onion, bell pepper, and a couple large pinches of salt and pepper.
Cook, stirring frequently, for 5-6 minutes.
Add garlic and Lawry’s seasoned salt and cook for 1 minute, stirring frequently.
Sprinkle flour over the veggies and stir to combine. Cook, stirring frequently for 1 minute.
Slowly pour in about half a cup or so of the chicken broth, stirring everything together until the chicken broth cleans the bottom of the pan.
Reduce heat to low and stir in remaining chicken broth and heavy cream until well combined, smooth, and creamy. Add a couple pinches of salt and pepper.
Stir in about ⅔ of the cheese (about 2 cups) until it completely melts into the sauce.
Stir in Rotel tomatoes (DON’T DRAIN!) and shredded chicken.
Season to taste with salt and pepper.
Carefully add pasta and toss to coat evenly in the sauce. Mix until well combined.
Top casserole with remaining cheddar cheese.
Bake uncovered for 20 minutes. Let sit for 5 minutes.
Garnish with sliced green onion and parsley and enjoy!
