Cold and Creamy Chicken Pasta Salad

1 pound boneless skinless chicken breasts
3 ounces butter
1/2 pound rotini pasta
2 teaspoons salt
2 quarts water
3 teaspoons salt
2 cups sour cream
3 cups mayonnaise
2 teaspoons dill weed
2 teaspoons cracked black pepper
1/2 cup parmesan cheese
2 ripe avocados

Lightly sauté the chicken breasts until tender. Cut into strips about 1/2" wide an 2" long. Bring the water to a boil over High heat and add the salt. Add the pasta and turn the heat to Medium until pasta is tender, not mushy. Drain and rinse with cold water. Set aside. Mix salt, sour cream, mayonnaise, dill weed, black pepper and parmesan together and allow to set for 15 minutes so that the flavors all blend together.
Peel and pit the ripe avocados. Slice into half inch strips, lengthwise. Mix the chicken strips, pasta and dressing in a large bowl. Mix should be slightly juicy. Gently stir in the avocados, so they don't break up. Allow the mixture to set overnight so that the pasta absorbs the dressing.

If the mixture is dry the next day, add mayonnaise so that it is slightly wet. Taste for seasonings.

To serve: place chicken pasta mixture in a chilled serving bowl and garnish top with ripe tomato wedges. Sprinkle with a small amount of dill weed.