What is this cut of meat? Ideas on what to make?

It's difficult to guess based on the cut alone, as they butcher animals differently in the US / UK / France / Russia (and Jewish and others), which can result in cuts that aren't easily recognizable in other countries.

I'm going to assume pork, due to the variation in meat color. (it's possible that it's an issue in monitor calibration, but the top left of that first picture is way more 'pink' than 'red' as compared to the muscle to the right of it. You don't typically see that significant of color change between two adjacent beef muscles, nor that pale of a color in beef)

Without being able to smell it and feel it knowing how big it is (there is no frame of reference as that plate could be a saucer) and how long it was frozen for and how, it's really hard to say with 100% certainty whether this is beef, lamb, pork or dinosaur meat. ;-)

However it contains bone, fat and meat, so add some butter in a kettle, throw the meat in and lightly fry it on all sides, add your favourite spices, a bottle of dark beer and roughly chopped onions and let it boil in the beer with a lid on the kettle until the meat falls off the bone, and come back and tell us what kind of meat it was!

:-)

_{66% chance it's pork though, 22% it's beef that was slightly discoloured by being frozen for too long and a little more discoloured in the top left by bad packing, 11% it's lamb and 10?¹¹ % chance it's dinosaur meat. ;-)}

Looks like a pork shoulder. It's a common cut for smoking, or pulled pork BBQ. You could braise it.

Fatty roasts always respond well to slow cooking, either in the oven or in a smoker, or in a stew or braise. That goes for beef as well as pork. Cover it with your favorite spices, put it in the oven, fat side up, cook it at a low (325F/163C) temperature until it's soft enough that you can pull it apart with a fork.

I am quite sure this is pork. Where I come from, we make broths and soups with this cut.

Looks like beef chuck roast. Make a nice stew. Even if not beef it should still make a good stew or pot roast

Chuck roast from what I can tell.

Cube it up and drop in a crockpot add veggies and potatoes with some stock or water if you don’t have any.

The first picture shows a curvy thin bone which gives a hint. I'd say it is some sort of pork cut that includes ribs like pork loin chops, porc rib.

Here are a few similar images the the lining layer of fat and bone