01 - Boil rotini or penne in generously salted water until al dente, following package directions. Drain in a colander, rinse under cold running water to halt cooking, and spread out to cool completely.
02 - In a large mixing bowl, whisk together mayonnaise, sour cream, and ranch seasoning mix until smooth. Stir in 1 tablespoon of milk; add a second tablespoon if a thinner consistency is preferred.
03 - Add the cooled pasta to the dressing and toss thoroughly until every piece is evenly coated.
04 - Gently fold in the halved cherry tomatoes, diced bell pepper, shredded cheddar, bacon bits, sliced green onions, and thawed peas. Mix until evenly distributed throughout the salad.
05 - Taste the salad and adjust salt or pepper as needed. Cover and refrigerate for at least 30 minutes to allow the flavors to meld before serving.