Sprinkle salt, black pepper, and dried sage on chicken, dredge in flour, shake off excess. Add oil to a skillet, turn to medium-high heat and lightly brown chicken on both sides, remove and place on a paper towel.
Add yellow onion to the same skillet and saute until tender, about 4 minutes. Add garlic and saute one additional minute.
Add carrots, potatoes, onions, garlic, and celery to slow cooker. Place chicken on top, pour chicken broth over chicken, add additional salt and pepper to taste, cover and cook on low 6-8 hours or until chicken is falling off the bone.
Add peas the last 15 minutes of cooking time.
