Season the chicken with salt and pepper. Heat 1 tablespoon of oil in a pan over medium-high heat and fry the chicken until cooked through and browned; about 5-6 minutes on each side.
Cook the green beans in slightly salted water until they are crisp-tender. Remove from heat, drain and rinse with cold water.
Cut off the skin of the grapefruit and divide it into segments. Do this over a bowl, so you keep all the juice for dressing.
To serve, divide the lettuce leaves between plates, then top them with green beans, grapefruit, and chicken. Drizzle with the grapefruit juice and season with salt and pepper to serve.