Bring a large nonstick pot of salted water to boil. Follow package directions to cook tortellini.
In a small bowl, stir together paprika, Italian seasoning, salt, and pepper to taste.
If you marinated the chicken, drain chicken from the buttermilk. If not, cut chicken into even, bite-sized pieces. Dab chicken pieces with paper towel and toss to coat in the seasoning mix.
Add the flour on top and stir until chicken pieces are coated.
In the same pot used to cook the tortellini (must be a nonstick pot) add 3 tablespoons reserved olive oil from the sundried tomatoes. Heat on medium for about 30 seconds, then add a sprig of basil and the garlic. Stir for another 30 seconds, then increase heat to medium and add the chicken.
Cook chicken, stirring occasionally, until cooked through and no longer pink inside. If needed, add additional sundried tomato oil.
When chicken is almost cooked through, remove the basil and add the sun-dried tomatoes and sauté until chicken is cooked through.
Add drained tortellini back in with the chicken and reduce heat to low. Gently stir for 1–2 minutes and remove from heat.
Stir in the basil pesto and 1–2 tablespoons of oil from the sundried tomatoes as desired. Taste and season with salt and pepper and red pepper flakes if desired.
Garnish plates with fresh basil and add Parmesan cheese.
