Preheat broiler. Line a baking sheet with foil.
To make the spice blend, crush the fennel seeds and red pepper flakes in a spice grinder or chop them very finely with a knife. In a small bowl, combine the chopped fennel seeds, red pepper flakes, chopped fresh rosemary, chopped fresh thyme, paprika, kosher salt, and black pepper.
Place the chicken on the prepared baking sheet and tie the legs together (optional). Rub the outside of the chicken, first with the olive oil and then with the spice mixture, until evenly covered. Place under the broiler until the skin becomes crisp and dark golden brown.
While the chicken is under the broiler, prepare the crock-pot by adding the potato, onion, garlic, bay leaves, chicken broth, rosemary sprigs, and thyme sprigs to the pot. Finally, place the chicken on top and put the lid on the crock-pot. Cook on high for 4-5 hours or until the chicken is tender and cooked through. Serve immediately or shred and save for later.