Shred the cabbage and carrots with your food processor. Put in a large bowl.
Slice up the green onions and add to the coleslaw/carrot mixture.
Combine the mayo, sugar, vinegar and celery seed, salt and pepper. Shake it up in a jar. Taste this to make sure it's seasoned properly.
Add it to the cabbage/carrot mixture until well moistened. Taste again...if it's too sweet add either more vinegar or may to make it a bit more tangy. Store in a container in the fridge until well chilled.