Bring a large pot of salted water to a boil. Cook rotini according to package instructions until al dente. Drain and set aside.
While pasta cooks, season chicken cubes with 1 tablespoon of Cajun seasoning, salt, and pepper.
Heat olive oil in a large non-stick skillet over medium-high heat. Add chicken and cook for 6-8 minutes until golden brown and cooked through.
Add minced garlic to the skillet and sauté for 60 seconds until fragrant.
In a blender or food processor, combine the cottage cheese, milk, and the remaining 1 tablespoon of Cajun seasoning. Blend until completely smooth.
Reduce skillet heat to low. Pour the blended cottage cheese sauce into the skillet with the chicken.
Add the cooked rotini, shredded cheddar, and Parmesan cheese to the skillet.
Stir continuously over low heat for 2-3 minutes until the cheeses are melted and the sauce coats the pasta thoroughly. Do not boil the sauce to prevent curdling.
Garnish with fresh parsley and serve immediately.