Cook the Pasta
Bring a large pot of salted water to a boil. Cook the pasta according to the package instructions until tender but slightly firm. Drain, rinse briefly with cold water, and allow it to cool completely.
Prepare the Chicken
Cook the chicken breast until completely done. Season with salt and black pepper if desired. Allow it to cool, then cut or shred it into small pieces.
Prepare the Vegetables
Cook the peas until tender and allow them to cool. Drain the sweet corn. Chop the pickled cucumbers and mushrooms into small pieces, and finely chop the parsley or dill.
Combine the Ingredients
Place the cooled pasta in a large bowl. Add the cooked chicken, peas, corn, pickles, mushrooms, and fresh herbs. Mix gently.
Make the Dressing
In a separate bowl, combine the mayonnaise, lemon juice, salt, and black pepper. Mix until smooth.
Add the Dressing
Pour the creamy dressing over the pasta mixture. Gently mix until all ingredients are evenly coated.
Chill and Serve
Cover and refrigerate for about 2 hours. Serve the pasta salad cold.