Directions

1. Discard skin from chicken and sprinkle chicken with 1/2 tsp. each salt and pepper. Place chicken in a single layer (if possible) in a 6-qt. slow cooker with the bone side down. Cut lemon in half. Squeeze juice from half and cut remaining half in round slices or wedges; set aside.
2. In a measuring cup, stir together wine, mustard, butter, reserved lemon juice, and garlic. Pour mixture over chicken in slow cooker. Top with 2 oregano sprigs.
3. Cover slow cooker and cook chicken on low setting until meat is cooked through and an instant-read thermometer inserted into thickest part reaches 165°F, 2 1/2 to 2 3/4 hours. Transfer chicken from slow cooker to a platter and tent with foil.
4. Whisk together flour and cold water in a small saucepan. Slowly whisk in 1 cup juices from slow cooker. Bring to a boil, whisking; then reduce heat and simmer about 5 minutes to blend flavors, whisking occasionally. Season with salt and pepper to taste.
5. Uncover chicken and spoon sauce over it. Sprinkle with oregano leaves and tuck in reserved lemon slices or wedges. Top with more oregano sprigs.