Celeriac is a root vegetable that tastes of celery. If added to a stew, it will take on the flavour of the stew, so its own flavour will be less pronounced. I have found that celeriac really comes into its own when not part of a stew. It has a lovely creamy texture. So it can be cut up into little matchsticks and added to a stir fry. Or it could be steamed on its own or with other vegetables (best cut up). If the taste of celery is really liked, then it could be added to mashed potatoes and cabbage to make a really tasty bubble and squeak. Or it could be used raw in a salad. The main downside with the vegetable is that it needs a good peeling which lowers the nutrient value. But apart from that it keeps well and is worth a try. It adds variety to our ever diminishing choice of unprocessed food.
Of course, if the taste of celery is disliked, then celeriac is unlikely to be liked in whatever form it is cooked in.