Place chicken, potatoes, onion, carrots, celery, and corn into a 6-qt slow cooker. Stir in chicken broth, garlic, thyme, oregano, cayenne pepper and bay leaf; season with salt and pepper, to taste.
Cover and cook on low heat for 7-8 hours or high heat for 3-4 hours.
In a small bowl, whisk together half and half and cornstarch. Stir in half and half mixture and butter during the last 30 minutes of cooking time.
Heat a large skillet over medium high heat. Add bacon and cook until brown and crispy, about 6-8 minutes. Transfer to a paper towel-lined plate.
Serve soup immediately, topped with bacon and garnished with chives, if desired.
Notes
*Half and half is equal parts of whole milk and cream. For 1 cup half and half, you can substitute 3/4 cup whole milk + 1/4 cup heavy cream or 2/3 cup skim or low-fat milk + 1/3 cup heavy cream.