In a large pot or Dutch oven melt the butter over medium heat and add the onion. Saute the onion until translucent, about 3 to 5 minutes.
Add the flour and toss to mix, cooking for 1 minute, using a wooden spoon to scrape any browned bits off the bottom.
Place the corn in the pot and cook for 1 additional minute, until just heated.
Stir in the sugar, cream, and milk and let cook, stirring occasionally, for about 5 minutes.
Using a slotted spoon remove 1 1/2 cup of the corn and set it aside in a bowl. Blend the remaining ingredients using a handheld blender or a stand blender, making sure to leave some bits of corn (the mixture should be lumpy and not perfectly smooth).
Return the corn to the pot and season it with salt, pepper, and fresh thyme.