Fish for the finicky

I'd try a mild fish like cod. Do something basic, like bake it. Make some side dishes you know he likes - and offer up some condiments if that makes your Hubby feel 'safe' - like cocktail sauce - something to dip the fish into.

A well-seasoned salmon tastes delicious, and to me doesn't seem too fishy. Baked or pan-seared.

i'm also finicky, but push myself. took me awhile to like salmon, cooked in an air fryer with lots of lemon or soy garlic sauce to cover the "fishy" taste, which is the major turnoff. i only buy frozen or canned fish, skinless and boneless, not fresh fish, which has greater potential for spoilage and what causes the fishy smell.
i suggest to try him out on fried fish. i make tuna or salmon patties.
use either 1 can of tuna-solid white or 1 can of trader joes alaskan pink salmon, boneless + skinless. (i can't even look at bones or skin let alone eat them).
1. in a bowl add 2 tbsp of egg whites or 1 sm egg- (too much liquid will make patties hard to form and you'll have to dry out mixture with too much bread crumbs).
2. whisk in garlic powder, i put alot because i like garlic with fish
3. can add capers or chopped up green olives or pickle relish, +/or 1 tsp of dijon mustard, to your, or his, taste.
4. add fish and mix well.
5. add no more than 1/8 to 1/4 cup of almond flour, for keto/low carb diet, or bread crumbs, panko works well for very crispy texture. (i use almond flour then roll the formed patty in a little panko crumbs.
6. mix well and form patty, can put an outer layer of panko crumb on the patty for extra crisp
7. fry in avocado oil or spray with oil and put in air fryer.
8. serve with an aioli or horseradish sauce or mayo - which my husband puts on everything.

Fish tacos (I use cod) for the win!

How about shrimp? I love using shrimp in tacos, pasta, or just by themselves with some veggies. Many ways to season them too.

If he likes asian food, my mom's Chinese contact fried fish is a great way to make it. Make it with any mild white fish fillet such as cod, haddock, tilapia, pangasius. I suggest a mild fillet because he probably hates dealing with fish bones, and the sauce in this dish is so strongly flavoured so you won't notice you are eating fish.

For two people finely dice a cubic inch of ginger. Slice the ginger thinly against the grain first to avoid any stringiness. Finely dice three or four spring onions. Place fish in a rimmed serving dish and cook in the microwave until flesh is opaque. Cover the cooked fish with the ginger and spring onion. Flavour with a couple of large glugs of soy, a large pinch of sugar, a splash something alcoholic (sake, rice wine, dry sherry, dry vermouth, even a little gin), something acidic (juice of half a lemon or a whole lime or a splash of vinegar. Bring to the table. Heat up a quarter cup of vegetable oil in a small saucepan until very hot. Use your nose, when you can start to smell a whif of smoke it is as hot as you can get it. Carefully pour hot oil all over the herbs to blend the flavours. There will be a lot of dramatic sizzling noises. Serve with rice and some cucumber salad.

My husband is just the opposite. He will only eat fish, and I respect that. Since your husband eats and likes red meat, I'd start introducing white meat and reducing the red. See what he accepts and likes and go from there. Once he is used to white meat, he may try fish. Swordfish has the flavor of meat, and my husband won't touch it even though it's technically "fish". Prepare fish for the rest of the family and he just might try it himself with no prodding. However, we have a cousin who cannot abide fish, taste or smell, and will never eat it. Your husband can be very healthy eating more white meat.

PS: You might want to send him on a fishing trip with "the guys" to Canada or remote lakes in the USA. They are flown in, fish all day, and then pan fry their catch. After a week you just might have a fish lover.