Egress with encryption

Hi -
This is a technical question and I am wondering how to achieve it.
I have two Kubernetes clusters. I would like to set up a tunnel between the two clusters using stunnel in one side and nginx in the other.
All TCP traffic going out of the first cluster will need to transit through stunnel.
This TCP traffic will be encrypted using stunnel and then offloaded at the nginx ingress controller of the destination cluster.
I would like some guidance on how to achieve the egress tunnel. i.e. How to configure stunnel “service” to tunnel traffic from one cluster to another cluster.
Thank you