Can I still claim back money lent to a friend with an expired cheque?

I have lent money to my friend multiple times over the last year with cheques as a guarantee.

Unfortunately, the cheque expired 2 days ago and he has not paid 90% of the money since he says he has no funds anymore.

I have bank statements to prove the transfer to his account. I need your advice to see if I can raise a court case against him and what will the process be.

Thanks