You could infuse it in oil, extra virgin olive is good...
or chop it and freeze it in ice cubes...stays good for months...
eat it in salads etc...
we especially like Courgettes stir fried with loads of chopped Tarragon...
You can also infuse it in honey, which means it's oils will keep for years...
it is also possible to extract its oils by infusing in alcohol 40% or better, then you can use it as it is (nice tasting drink..or liquer it by the addition of sugar and glycerin, add it to salad dressings for an 'extra' kick, or use it to flavour casseroles etc (best to add a shot to the wine you would use in such recipes (it destroys the alcohol but you keep the flavour..