Preheat the grill. Season the chicken with salt, pepper, and 1 1/2 tablespoons of olive oil. Place the chicken on the grill and cook for about 4 minutes on each side, or until cooked through and nicely marked by the grill. Brush the pineapple slices with the remaining olive oil and season lightly with salt and pepper. Place the pineapple slices on the grill and cook for 1 to 2 minutes on each side, or until the fruit is slightly softened and nicely marked by the grill. Remove from the grill and cool. Reserve 4 slices of the pineapple and dice the rest of the fruit. Dice the cooled chicken. In the bowl of a food processor, add the 4 reserved slices of fruit. Process until mostly smooth. While the processor is still running, add the walnut oil in a steady stream until combined and emulsified. Stir in the chervil and season the vinaigrette with salt and pepper. In a mixing bowl, toss the diced chicken, pineapple, red onions, celery, and walnuts with the dressing. Cover the salad and refrigerate for 1 hour.
Heat the vegetable oil in a non-reactive and heavy-bottomed pot until 350 degrees F. Add wontons slowly to prevent the oil from bubbling over. Fry the wontons for 30 seconds or until crispy. Drain on paper towels and season with salt and sesame oil.
Serve chicken salad on top of Bibb lettuce leaves and garnish with chopped parsley and fried wontons.
This salad does not keep well and should be prepared no longer than 1 to 2 hours before serving. (The acid in the pineapple juice continues to "cook" the chicken and if left for any length of time, the chicken meat becomes soft and mushy.)