Multiple boot entires in BIOS?

Gigabyte GA-Z170-HD3

BIOS version F6

i5 6600 K

32 GB DDR4 2400 RAM

RX580

iMac17,1

OpenCore 0.9.5

​

Hi everyone,

I started off troubleshooting something different but discovered a bigger problem:

Every time I reboot, a NEW boot entry is made in my BIOS. I now have over 30 entries. Eventually this will probably prevent booting, I guess.

How do I delete the additional entries and how do I prevent even more entries from being made?

Thank you.