Hey gemm.
I live in Manchester and there are loads of places in town to get a jacket potato with beans. There's a stand on the main high street called "what a potato", in the Arndale food court theres a potato place but my favourite is in the food bit of the Arndale Market. There's a lady who does jacket pots with beans and she does you these nice big side salads so perfect for Extra Easy! You can also buy loads of dead cheap fruit in the Arndale Market, I once got a punnet of strawbs for a pound!
If you're going for a lunch in the northern quarter, I've been to Oklahoma cafe a couple of times. It's a bit hippyish and the staff are rude but it does the most amazing options for slimming world- baked sweet potatoes and the best toppings- feta, beetroot, mint and apple is to die for!
Hope that helps xxxx