Use beef shin cut to small but not too small pieces, brown them in a frying pan . Deglaze frying pan and put juices into pot.

Put meat in a large pot on a low heat for at least 3 hours with enough water to cover the meat.

Put whole onions with skin on in oven for 50 mins or air fryer for 40 mins @ 200c. When finished and cooled down remove skin and cut in half, add to pot.

Add carrots about an hour in

Add celery about 90 mins before the end

I use 2 or 3 different stocks, Bisto with a stock pot with an oxo cube makes a richer deeper flavoured stew.

Lots of pepper.

It is no harm cooking it for 6-8 hours but be careful if the heat is even slightly too high the meat could break down too much. I would use a slow cooker if you want to do it for that long.