Toss chicken with salt, pepper, garlic powder, paprika, and cornstarch until coated.
Heat the tomato oil in a large deep skillet over medium-high heat. Sear chicken in a single layer 3 min without moving, toss, 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 dry orzo. Stir to coat 30 sec. Add all 2½ cups of stock. Stir to combine. Bring to a gentle simmer. Reduce to medium-low.
Cook uncovered 10 to 12 minutes, stirring every 2 minutes, until orzo is al dente and stock is mostly absorbed.
Reduce to low. Add cream, red pepper flakes, and Italian seasoning. Simmer gently for 3 to 4 minutes.
Add spinach. Stir until wilted 60 sec. Remove from heat.
Add Parmesan in 3 stages off heat, stirring fully between each.
Return chicken. Fold gently. Taste for salt. Scatter basil off the heat. Serve immediately.