A pre-marathon meal needs to pack a real carbohydrate punch to provide plenty of energy for the gruelling task ahead. Most meals are pasta-based, but you may find rice a better choice; it provides just as much carbohydrate but is easier to digest and less likely to cause bloating.
Ham provides easily digested protein, and mushrooms and peas provide plenty of vitamins and minerals. Aim to have your last main meal at least three hours before you run. After that, drink plenty of fluids and, about 30 minutes before you run, have a small snack such as a banana.