E-Series controllers don't currently support FCoE directly. However, if you have an FC host interface card in the Nexus 5k, you should be able to do this:
1) Connect the E5600 via 16Gb FC to the 5k
2) Create virtual fibre channel ports for the ethernet host ports on the 5k that you want to zone with the FC ports connected to the E5600
3) Create your VLAN(s), and a VSAN (all FCoE traffic requires a VSAN).
4) Add the VFCs (virtual fibre channel ports) from step 2 and the E5600 connected FC ports from step 1 to the VSAN
5) Create the VSAN-VLAN map (if needed)
6) Zone the desired VFCs and the E5600 FC connections