1To prepare the dressing - in a small bowl combine the olive oil, balsamic vinegar, the freshly squeezed lemon juice. Whisk well and season it with salt and freshly ground black pepper to taste.
2Heat the grill.
3Cut each peach to 8 crescents. Trim the fennel bulb and cut it length wise to 1/4 inch thick slices.
4Lightly brush the pieces with olive oil and place them on the heated grill. Cook each side until it gets dark grill marks, about 2 minutes each side.
5The salad can be served in the individual plates or in a big flat serving plate. Place the arugula on the plate; arrange the grilled peach and fennel pieces on top. Add the gorgonzola cheese crumbles. Right before serving drizzle with some of the dressing.