Bring a large pot of generously salted water to a boil. Add the rotini and cook until just al dente according to the package directions. Drain well, then rinse under cold water to stop the cooking and cool the pasta completely. Let the pasta sit in the colander for several minutes so excess water can drain off before mixing the salad. Excess moisture will thin the dressing.
1 lb (454 g) rotini pasta
While the pasta cools, chop the rotisserie chicken into bite-sized pieces. Chop the sun-dried tomatoes and roasted red peppers, thinly slice the red onion, and roughly chop the basil.
2 cups (280 g) chopped rotisserie chicken, ½ cup (85 g) drained and chopped sun-dried tomatoes in oil, ¼ cup (40 g) drained and chopped roasted red peppers, ½ cup (80 g) thinly sliced red onion, ½ cup (12 g) chopped fresh basil
In a medium bowl, whisk together the mayonnaise, grated Parmesan, oil from the sun-dried tomato jar, lemon juice, red wine vinegar, Dijon mustard, grated garlic, kosher salt, Italian seasoning, and black pepper until smooth and fully combined. Using the oil from the jar gives the dressing a more concentrated tomato flavor throughout the salad instead of only in the tomato pieces themselves.
¾ cup (168 g) mayonnaise, ¼ cup (22 g) grated Parmesan cheese, 3 tbsps (45 ml / 40 g) oil from the sun-dried tomato jar, 2 tbsps (30 ml) fresh lemon juice, 1 tbsp (15 ml) red wine vinegar, 1 tsp (5 g) Dijon mustard, 1 clove garlic, ½ tsp (3 g) kosher salt, 1 tsp (1 g) Italian seasoning, ¼ tsp (0.5 g) finely ground black pepper
Add the cooled pasta, chicken, sun-dried tomatoes, roasted red peppers, red onion, and basil to a large mixing bowl. Pour the dressing over the top and fold everything together until the pasta is evenly coated and the ingredients are well distributed.
Cover and refrigerate the pasta salad for at least 30 minutes before serving. Chilling gives the pasta time to absorb some of the dressing and helps the flavors come together.
Stir the pasta salad again before serving. If the pasta has absorbed too much dressing after chilling, add a small spoonful of water or a squeeze of lemon juice to loosen the texture and refresh the dressing.