Cover the lentils and bay leaves with water and bring to a boil. Lower heat, and cook for another 20-30 minutes until soft. Drain the lentils and remove the bay leaves.
Mix the vinegar, stock, and oil. Season with salt and pepper.
Mix the lentils in with the sauce.
Cut the figs into quarters. Lightly shred the ham. Cut the Gruyère AOP into thin slivers with a peeler. Pluck the basil leaves off the stems.
Mix all the ingredients in with the lentils and serve directly on plates.