11. In a large skillet, heat oil over medium-high. Season pork with salt and pepper and cook, turning occasionally, until browned on all sides, about 8 minutes. Transfer pork to a 5- to 6-quart slow cooker. Reduce heat to medium and add onion, garlic, celery, and fennel seeds to pan; cook until onion is softened, about 4 minutes.
22. Add wine and cook, scraping up browned bits with a wooden spoon, until reduced by half, about 2 minutes. Add to slow cooker along with tomatoes. Cover and cook on high until pork is very tender, 4 hours (or 8 hours on low).
33. Transfer pork to a cutting board. With two forks, shred meat into bite-size pieces, discarding any large pieces of fat. Skim fat off sauce and discard. Return shredded pork to slow cooker and stir to combine. (To store: Cool, cover, and refrigerate up to 3 days.) Serve over couscous.
Take a few minutes to brown the pork and saute the other ingredients before adding them to the slow cooker -- it gives the dish deep flavor.