In a medium bowl, whisk together mayonnaise, relish, sugar, Dijon mustard, vinegar, salt, and pepper until smooth and creamy, about 2–3 minutes.

While the dressing sets, dice ham and cheddar cheese into ½-inch pieces. Finely chop bell pepper and onion, and measure out frozen peas. Chop fresh parsley.

Bring a large pot of salted water to a boil. Add bow tie pasta and cook according to package instructions, typically about 9–11 minutes, until al dente. Drain and rinse under cold water.

In a large mixing bowl, combine cooled pasta with diced ham, cubed cheddar cheese, chopped bell pepper, minced onion, frozen peas, and chopped parsley. Fold ingredients together.

Pour the prepared dressing over the pasta mixture and toss gently to coat evenly.

Cover the bowl with plastic wrap or transfer to an airtight container, then refrigerate for at least 1 hour before serving.