Toss chicken pieces with salt, pepper, garlic powder, paprika, and cornstarch until evenly coated.
Heat tomato oil in large skillet over medium-high. Sear chicken in a single layer 3 to 4 min without moving, then toss and sear 2 more min until golden and 165°F / 74°C. Transfer to plate.
Same pan, add garlic, stir 60 sec. Add tomato paste, stir 90 sec until brick red. Add sun-dried tomatoes, stir 30 sec.
Add wine to scrape the pan bottom. Reduce 90 sec. Add stock, reduce for 2 min. Reduce to medium-low. Add cream, red pepper flakes, Italian seasoning. Simmer gently 3 to 4 min.
Meanwhile, boil rigatoni in well-salted water until 1 min before al dente. Reserve ½ cup pasta water before draining.
Remove sauce from heat. Add Parmesan in 3 stages, stirring fully between each.
Add 3 tbsp pasta water to sauce. Add drained pasta. Toss over low heat 60 sec. Add more pasta water tablespoon by tablespoon for correct consistency.
Return chicken. Toss gently. Taste for salt. Scatter basil off heat. Serve immediately in warmed bowls.