Chop onions, celery, and potatoes.
Shred carrots and zucchini.
Add all ingredients, except half and half, to the crockpot.
Rinse out the cream corn can and pour over the ingredients.
Cook on high for 6 hours.
Remove ¾ of the vegetables and liquid to a bowl.
Purée with an immersion blender.
Return to crockpot.
Add half and half.
Stir together and replace the lid.
In a separate bowl, stir together ingredients for topping.
Serve by the bowl with corn relish on top.