Prepare chicken. Cut each chicken breast open and in half to make 4 thin chicken filets. With a meat mallet, pound each chicken breast to the size of the bun. Season chicken with salt, pepper and paprika.
Grill chicken and buns. Butter the top and bottom buns, set aside. Heat grill to high heat. Put the chicken on a grill and grill for about 4 minutes per side. Remove from the grill and add buns, just to toast, about 2 minutes. In a small bowl, combine mayo and blue cheese. Stir to incorporate.
Finish. To build sandwich start with avocado and hard boiled eggs on the bottom. Place the chicken filet on top of that. On top of the chicken, place a few sliced of tomato, two slices of bacon and some shredded lettuce. Smear the top bun with some blue cheese mayonnaise.