Instant pot 10 minutes beyond the required cooking time.

Short ribs!

Fatty meat in a crock pot cooked all day. You could do chuck roast, pork roast. Cook with broth also.

For stove - meatballs, meatloaf.

The secret: low and slow. So yes, braised beef/lamb, or any other protein cooked over time.

If you don't have time for slow-cookers, try using an instant pot/pressure cooker.

https://reclaimingyesterday.com/instant-pot-moroccan-lamb-stew/
https://damndelicious.net/2018/04/12/instant-pot-pot-roast/
https://www.rachelcooks.com/instant-pot-pork-loin-roast/

Any chicken dish in an instant pot is going to end up at least as tender as baked, but IME, much more so. Chicken tends to shred easily after cooking in an instant pot too, and you can do noodles/rice with it. Something like this may not be a great fit after stomach surgery, but you get the idea: https://www.jocooks.com/recipes/instant-pot-creamy-ranch-chicken/

You might also try velveting beef, like you do when making beef and broccoli: https://www.masterclass.com/articles/velveting-beef

Pot roast

Make stew from chicken, beef or pork.

Chicken would require least time.

Pork shoulder or butt or tenderloin cut into small pieces, would need may be 1.5 hours stewing at low boil heat.

Beef would need 3-4 hours (stew meat, or tenderloin, or chuck roast.

Cottage pie. It is easy to make, easy to eat and delicious. You can find recipes all over the internet. DH makes the simplest version which just includes ground beef(flavored by oxo cubes) and potato, and everybody likes it.

Instant Pots are good at tenderizing meat in a short amount if time. Any recipe that has some broth, like couscous or beef bourginon. First cook the meat for about 10-20 min then open the pot (I open it on my balcony to avoid odors in the house) and add the vegetables and cook another 10-15 min. I cook shorter times but those time settings will really make the food soft.

Shepherd's pie. Frozen or fresh-made.

Congee with ground meat.

Do you have a pressure cooker or instant pot? Pot roast, boeuf bourguignon, baby back ribs, pulled chicken are super tender and full of moisture when pressure cooked. If he’s open to Korean food, galbi jjim or dak jjim in the instant pot is tender and delicious.

Also, rice dishes like risotto with very small pieces of meat is an option.

How about fish? It’s soft and flaky. You could mash it up and mix it with rice in a casserole. Just make sure you check very carefully for bones. I’ve even found bones in canned fish n occasion.

Pulled pork?

I know this isn’t what you had in mind, but vienna sausages tend to be really soft. They also make something similar for toddlers. I think they’re called meat sticks?

What about meat sauce and pasta? Barely any chewing at all, really.

I would do meatballs

My elderly father can only eat soft food due to a stomach surgery. He is eating things like eggs, mashed potatoes, rice, lentils, cottage cheese, etc. But meat is especially challenging, and I am looking for recipes for meat that requires virtually no chewing (no dental issues, but he gets tired of chewing a piece of meat to the point it is ground up enough that it is safe for him to swallow) with a good amount of moisture (any dry is a no go). I rarely cook red meat, but I'm thinking some kind of braised beef or lamb might be best for this? Or could chicken work too? Any thoughts (and recipes) would be much appreciated.