Melt the butter and miso with the warm water
Add a touch of salt and pepper
Pour mixture over onions so it covers them halfway in the tray
Cook covered in foil at 450°F for 35 minutes
Remove from oven and evenly baste the onions
Put back in the oven uncovered for another 45 minutes
Continue to baste every 10 minutes until ready to serve
Cut onions in quarters for more even cooking and individual portions
