Been there done this many times. First, ignore all those posts telling us a little power slide donut action is all you need. I'd bet good money not one of those posters can power slide an ST1300 more than a second on a dirt 2 lane gravel road before it hits the dirt.
You need to stop and think the turn around over. All you need is upright balance, either from your own brain and muscle or get some help. You must always keep the bike leaned a bit to favor the "up hill" side of the turn around. The down hill side will be to long in leg for you to maintain balance. I often slide my butt over off the seat to give the uphill leg more "length" forget the too long downhill side, it won't reach, keep it on the footpeg. The only way the turn around will happen is slowly point the bike up hill while turning the bars and go forward a bit, stop, turn the bars, back up a bit. Lay it down going to the uphill side if it has to happen.
If you need to turn around "turning right" go over to the other wrong side of the road, just make sure that the uphill leg (right leg in a right uphill turn) is used to hold the bike. The left leg won't have enough reach and boom over you'll go. On dirt roads I also look over the road for dips and high sides (just off into the grass even) that I can use to make the bike roll backwards when I stop the forward momentum kinda like bumping off a curb. Much easier to let the bike roll without pushing with the balance leg.
I used to visit Cheaha State park in Alabama yearly for a ride rally. The hotel parking lot was NOT FLAT anywhere, very steep off chamber off angle but nice marked parking spaces all over. We would just sit and watch bikes try to park and those who failed to think it thru often went boom, leg too short on one side. The reason I mention this is because we all could go practice our skills in a paved parking lot if you know of a bad parking lot in your area. We probably all practice this type of turn every time we ride as in we should be pulling into parking spots "uphill" so the bike rolls back out without much foot pushing.
I'll be waiting for those ST1300 gravel road power slide videos guys. I'd settle for you just power sliding it in the back yard grass. My attempts make the bike spin around maybe 20 degrees...