Using precooked chicken makes this recipe a breeze to prepare on busy weeknights.
Cook bacon in a large saucepan over medium-high heat, stirring often, until crisp and brown, 3 to 5 minutes; transfer to a plate with a slotted spoon.
Add onion and celery to rendered fat in pan; cook over medium heat, stirring often, until softened, 5 to 7 minutes. Add flour, and cook, stirring, about 1 minute. Add milk, and bring to a boil, stirring occasionally.
Add chicken, potatoes, corn, and cayenne; season with salt and pepper. Return to a boil. Reduce heat to medium, and simmer until heated through, 3 to 5 minutes. Serve sprinkled with reserved bacon.
When cooking the vegetables and flour in step two, stir frequently to prevent the mixture from taking on any color; this will keep the chowder creamy white.