"Cuban oregano" is a sp. of Plectranthus, it does not look like that to me. There are couple of forms of. variegated culinary oreganos in the genus Oreganum - yours could be one. It also resembles the basil Ocimum 'Pesto Perpetuo'.
Looks like periwinkle Variegated Vinca Major or Minor. Pretty blue flowers. I'll just check! It can run away with your garden and get invasive but I like it to twine round the shrubs in a bed that you can't give much attention. Looks attractive hanging over a wall.
I don't know what your zone is, but when I lived in Seattle, zone 8, I had vinca and it was terrible. You talk about INVASIVE? It would come up in my lawn 10 feet away. It really covered the ground if that is what you want, BUT, you just cannot control it unless you have time 24/7 to watch it.
Now, I will admit, mine was not variegated. If there is a difference in it's growth, good luck. We are in zone 5 here, and do not have some of the things like they do in Seattle because it gets so cold here in the winter. Things like Morning Glory. There, some roots of that are the size of my little finger. You might see little thin stuff here, but nothing like it is over there.
OK, I'll add it...do you all agree that is what it is. I am fairly certain that it had lavender/blueish flowers on it when I got the cuttings. That is what caught my eye, the contrast of the wh/gr leaves and the lt blue flowers. I can still take some side shots of the stems.