Slice corn off of cobs into LARGE bowl, scrape down the cobs with dull end of knife after slicing to capture juice. A little messy, choose a spot for easy cleanup. Using a small paper or plastic bowl upside down on bottom of large bowl helps.
Melt butter in large sauce pan or dutch oven
Add onion, salt & rosemary and sautee until onions are translucent (not browned), ~ 5 minutes
Add corn, sugar and turmeric to onion and cook over medium-high heat until liquid thickens, ~ 2 minutes.
Sprinkle corn meal in while stirring to combine.
Add cream, reduce heat to medium and cook until corn is soft, ~ 3 minutes.
Fish out rosemary sprig, add black pepper to taste.