Prepare the balsamic glaze. In a small pot, over medium heat, mix the balsamic vinegar and the honey. Bring to a simmer and cook, stirring occasionally for around 20 minutes until the vinegar has reduced and thickened. Remove from heat and transfer a glass jar.
Prepare the peaches. Heat the butter or olive oil in a small pan over medium heat. Add the peaches, and cook for around 2 minutes per side. Sprinkle with salt and pepper, and remove from heat.
Assemble the salad. Start by making a bed with the lettuce, top with the peaches, walnuts and blue cheese. Drizzle with the balsamic glaze and serve.