Rotisserie Chicken, Oven Baked Duck Fat Potatoes and Green Peas: I had purchased the cooked chicken last week, portioned and froze it. For this meal, I preheated the oven to 350F, added some duck fat and the sliced potatoes to a covered dish, and baked for 30 minutes. Then I topped the potatoes with the defrosted portions of chicken, recovered and returned to the oven for another 30 minutes to reheat the chicken and finish the potatoes. The peas were cooked in the microwave from frozen.