We co-exist with our ground elder. There are patches we do nothing about and patches we go at. We garden without chemical aids - I can't say organically because that sounds like we have a method and we aren't anything like organised - so the ground elder gets dug out a bit at a time. I quite enjoy that which is a good job since it's a year round job. We have had some success in eradicating elder from some beds. The veg plot stays more or less clear now. There's a border that we still haven't got to that invades the main plot but that's manageable. The rose bed is a bigger problem. We fork that over in the winter and through into the spring. Some always hides away under the bigger bushes and between stumps and walls but provided it doesn't annoy us we leave it alone. Other beds we mulch using leylandii litter and if that doesn't kill the elder it makes it a lot less tenacious and easier to root out if and when we can get around to it. I heard somewhere that the Romans introduced ground elder as a pot herb and if that's true there must be some recipes around. Maybe one day we might try seeing it as an asset??