This is a feasibility trial designed to explore whether liver, pancreas, and kidney transplant patients who receive a small patch of skin, transplanted onto their forearm (from the same donor as the solid organ), may benefit from this. The aim of this feasibility study is to assess whether this approach is acceptable to patients and clinical teams, and to inform the design of a larger trial. This patch of skin is called a sentinel skin flap (SSF) because it can act as an early warning system, potentially showing a visible rash if the transplanted organ is rejecting. By detecting signs of rejection earlier than current methods, the flap may help prevent damage to the transplanted organ.