Preparation Start by dicing the onion, the garlic and the carrots (or you can cut them in Julienne strips). Squeeze one of the grapefruits and put its juice aside. In a saucepan, add a jet of olive oil and the white wine. Whenever the fire is hot and the breasts seasoned, brown them for 3 or 4 minutes on each side before removing them. In the same saucepan, poach the garlic, the onion and the carrots by lowering the heat a bit and letting it cook for about 15 minutes. Afterwards, add the Sherry vinegar and the grapefruit juice and mix them well. Add the breasts again and let everything cook for 12-15 minutes. After that time, the chicken marinade should be ready. This dish is eaten cold. Therefore, it is important for it to be well soaked in the marinade. Hence, once it is ready and cold, let it stand in the fridge overnight inside a glass container. Presentation Slice the marinated breasts and place them on a plate. On top, decorate the breasts with the carrots and the poached onion and add some grapefruit slices in between them. As a side, you can prepare white rice or a corn salad, for instance.