If you opt to include eggs, place them in a large pot, cover with cold water and place on high heat. Once boiling, cook to your preference (12 min for hard-boiled, 6 min for medium-boiled, 3-4 min for soft boiled). Remove the eggs from the pot and set aside to cool slightly. Retain the boiling water for the beans.
Combine all the dressing ingredients in the bowl you'll be serving the salad in, whisking until well incorporated. Set aside.
Heat a non-stick pan on medium-high. Remove the chicken skin from your roast chicken and tear it by hand into the pan. Cook it for 4-5min until it crisps up. Then remove and set aside.
In the same pan, add 1 tablespoon of oil and add your bite-size chicken pieces. Cook for 4-5min, until heated through and lightly browned. Remove from pan and set aside.
In the same pan, add the remaining 2 tablespoon of oil and add your well-drained lentils. Cook for 5-6min until heated through and slightly crisped up, then set aside.
Add your green beans to the pot of salted boiling water. Cook for 4-5min until tender but still crisp and 'al dente'. Drain and add directly into the serving dish with the dressing.
Finally, assemble the salad by placing the lettuce, lentils, chicken, green onions, and chicken skin on top of the beans. Peel and quarter the eggs and arrange around the dish.