In a large skillet, heat the olive oil and add the onion and potatoes to the skillet (alternately, you can saute the onions and potatoes in the bacon grease instead). Sauté for 5 minutes.
Place the onion and potatoes into a slow cooker. Add the chicken broth, water, corn, Worcestershire sauce, sugar, and salt. Stir to combine the ingredients.
Cover and cook on low for 7 hours.
Remove half of the mixture and place into a blender or food processor. Blend until puréed and return to crockpot. Add the milk and butter. Take out a little bit of liquid and whisk the cornstarch into it. Add the cornstarch mixture to the slow cooker. Cover and cook on high for an additional hour. Sprinkle individual servings topped with bacon.