Halibut is a pretty versatile fish with a fairly mild flavor, so you've got some advantages here! Here are some ideas:
1. Serve with a homemade dill sauce
2. Cut into cubes and serve in caesar or spinach salad
3. Mix with cream of potato soup, corn chowder, crumbled bacon and half and half for a Seafood Bisque
4. Slice and place in soft flour tortillas, along with shredded cheese, coleslaw, and sauce for fish tacos
5. Toss chunks with fettucini alfredo