In a saucepan, combine potato and cold water to cover. Bring to a boil and cook for 2 minutes. Remove from heat. Cover and set aside. In a frying pan, heat oil over medium heat for 30 seconds. Add onions, celery and carrots and cook, stirring, until carrots are softened, about 7 minutes. Add thyme, bay leaf and flour and cook, stirring, for 1 minute. Add broth and white wine and cook, stirring, until mixture comes to a boil and thickens, about 4 minutes. Drain reserved potato and add to mixture. Season to taste with pepper. Arrange chicken over bottom of slow cooker stoneware and cover with vegetable mixture. Cover and cook on Low for 6 hours or on High for 3 hours, until juices run clear when chicken is pierced with a fork. Add peas and stir well. Cover and cook on High for 20 minutes, until peas are tender and mixture is hot and bubbly.