What kind of kidney for steak and kidney pie?

[refreshingseahorse]

I'm planning to make a steak and kidney pie. Looking at different recipes, some advise to only use ox kidney as lamb kidney will get tough if you slow cook it with the steak. Other recipes use lamb kidney and don't mention this problem. Ox kidney is tricky to find (although amazon sells it which is a bit disturbing).

Does anyone have any steak and kidney advice they can offer?

https://www.theguardian.com/lifeandstyle/wordofmouth/2012/mar/01/how-cook-perfect-steak-kidney-pudding This seems to suggest you can use almost any ....

In my experience any kidney will overcook if you add it for the whole duration the steak is cooking. I add it towards the end.

I wouldn't mix lamb and beef but I suppose it's preference. The flavour doesn't seem work well for me.

I add pork kidneys instead as I like the contrast with the beef. When I add 'ox' kidneys the flavour seems too samey and flat. It gives it a bit of a foil.

I prefer pigs' kidneys to ox for s&k, and only use lamb for quickly cooked dishes.

That's for a pudding, OP is making a pie.

I use pigs kidneys for pie or puddings. Lambs kidneys get split and grilled for our cooked breakfast or for devilled kidneys.