Place the chicken thighs, celery root, apple, onion, carrots, chicken broth, flour, thyme, salt, and pepper into the slow cooker. Stir once to distribute the flour.
Cover and cook on low for 6 to 7 hours until the chicken is tender and the vegetables are soft.
Remove the chicken to a plate and shred it with two forks, then return it to the slow cooker.
Stir in the heavy cream, Dijon mustard, and frozen peas. Cover and cook on high for 20 to 30 minutes until the peas are heated through and the sauce has thickened.
Notes
Add the cream and Dijon only after the long cook so the sauce stays silky and does not separate. If the filling seems too thick at the end, stir in a splash of extra broth. Leftovers reheat gently on the stove with a little broth to loosen the sauce. Skip the peas if you prefer a stricter low-carb version.Course: Main Course
Cuisine: American
Equipment: Slow Cooker, Knife, Cutting Board