if you mean Celeriac or celery root, I suggest not. It’s denser and has a stronger flavour. You could use quinoa to replace the barley but it will cook a lot quicker.
‘Cookies’ is also widely used in the UK too (adopted from our US cousins)…especially when they are in a jar! Traditionally we would call it a biscuit tin!
any beans in a tomato sauce will work (it’s a pretty forgiving recipe)…and why not include the pork too if that’s all you can find!