Pre-heat the grill to hot.
Thread the brioche fingers and nectarine wedges onto the skewers, leaving a little space between the pieces. Grill until the brioche is golden and toasted on both sides.
Remove and thread the brioche and nectarine wedges off the skewers. Put the brochettes back together, this time threading the mint sprigs in between the brioche fingers and the nectarine wedges. Serve immediately.