How do I create an EFI partition?

My mac has a problem: There is no EFI partition.

Here's the story. I had dual-booted linux with the Mac. I was looking in disk utility, when I noticed that my partition for MacOS had 300 gigabytes instead of 500. When I looked at the main hard drive, it said that my partition had 500 gigabytes, just like normal. But when I looked at the disk, it said 300. So I decided to troubleshoot it with my Linux OS. There, I found the EFI partition. I thought it was leftover from installing Linux, so...

I erased it before I knew that it was important.

Now, after erasing and reinstalling the OS, I am still without the EFI partition. Why is this? Is it because I'm not doing a clean install?

my Mac has a 1-terabyte hard drive that was recently replaced after the old one having a SMART error. The Mac OS works fine, but the neither the base system nor Linux are Bootable.

In order to deal with this problem, I am willing to do basically anything (that does not cost money, or require going beyond software).

And, although this has nothing to do with the problem:

This mac has 8 gigabytes of RAM, and has a 500-gigabyte partition on it with Linux Ubuntu.

It had a windows 10 disk image (virtualbox) before I erased and reinstalled the OS. This was configured to take up a Max of 100 gigabytes of data, and to only consume when needed. This was erased.

To fix the original problem, instead of just erasing the operating system, I had to copy a flash drive to it.