Pistachio Chicken Salad

I love this salad, however I do not at all like the dressing. Here's the full recipe though.

From the South Beach Diet book:

1/2 cup pistachio nuts, finely ground
1/2 + 1/4 tsp salt
1/2 tsp + 1 pinch freshly ground pepper
4 boneless, skinless chicken breasts halves
2 TBSP coconut oil
1/ cup diced sweet white onion
1 head romaine lettuce

Dressing
1 tsp grated sweet white onion
1 large, ripe avocado, peeled and pitted
3 TBSP extra virgin olive oil
3 TBSP lime juice
1 TBSP water

Preheat oven to 375 degrees. Mix nuts in a pie plate with 1/2 tsp salt and 1/2 tsp pepper. Press the chicken into the mixture. Heat 1 tbsp of the oil in a skillet and cook the coated breasts 2 minutes on each side. Place the breasts in a baking dish and bake for 15 minutes or until done. Heat the remaining oil in a skillet over high heat. Add the diced onion and the remaining salt and pepper. Cook until onion is browned. Line four plates with the lettuce. Slice the chicken breasts and arrange on breast on top of each salad. Sprinkle the onion on top of that. Serve with the dressing


Dressing: Puree all ingredients in a blender till smooth.