Now I understand your rational ! Dawn has given you pretty good directions for vegetative propagation. I use to own a plant n propagation greenhouse. Next Spring for you once the herb starts new growth will be your chance for cutting taking. Since we do not know if the plant seed is sterile or not take some seed, put in the refrigerator for few month to get the seed the seasonal break, then your late winter or early Spring take a few seed (less the 12 maybe). Use a shallow bowl n fold a paper towel with these seed between. Dampen the towel a lot n keep damp for at least 72 hours to 4 or 5 days. Keep in a warm area like the kitchen or small greenhouse. The long n short of this is to see if the seed are sterile or not. If they sprout … You should be able to grow from seed as well as softwood cutting.
As for edibity ! Take small amounts (leaves) n chew/taste n spit out. If not no off health effects … Try a little more in a day or two. Repeat this process using a little more several time couple days apart. What this process is check is to see if the plant is safe n truely edible. This is a test I teach in survival classes to test plant. Any odds effects the plant should be avoid n left to the bees. If all is well try using more n more to season meat, fish, poultry.
Next Spring or this winter try take any local college or biological society for actual I.D. Somebody somewhere does kNOW for sure what your plant/herb is.
Good luck n happy research !