Grill with a little butter on Bake with tomatoes, or in home-made tomato sauce - keep the sauce fairly thick as liquid will come out of the hake as it cooks Bake and then cover with any sort of sauce - parsley, hollandaise, cheese, beurre blanc etc
Haven't eaten hake for ages, but if I remember correctly, it can be fairly dry, so anything in a foil parcel or grilled/baked with a sauce should work.
or you could fry a load of veg in olive oil in a big frying pan - whatever you have, e.g. onions, garlic, leeks, tomatoes that no-one is going to eat, etc., then when they are softish, turn down heat, lay fish on top and cover with a plate. Serve with rice or potatoes.
Put each hake steak in a square of foil, add sliced mushrooms, olives etc. plus a splash of oil and some seasoning. Fold up foil to make a loose parcel, bake in the oven at 180 degC for about 20-25 minutes until the fish flakes easily off the bone and there is no pink showing. Open the foil for the last 5 mins of cooking. Easy and no messy pans to wash up.
Serve with baked tomatoes, mashed potatoes or rice or couscous and any veg or salad of your choice.