Preheat water bath to 58˚C using a sous vide machine or using low temperature poaching.
Marinate chicken fillets and place inside a food grade polyethylene bag. Vacuum seal and slow-cook bagged food in water bath for 6 hours.
Remove chicken from bag. Quickly sear or broil before serving. Serve with sauce.
For sauce, melt butter in a hot pan. Sauté bell peppers, garlic, onion, thyme and rosemary for 5 minutes. Add rum to flambé or create a burst of flame. Simmer until alcohol dissipates. Add cream and simmer for another minute. Season with salt and pepper. Puree using a blender or food processor. Strain sauce into a smooth consistency.