Heat a wide and shallow pan for about three minutes, then add the stakes in one layer (you can two it in two stags if they don't all fit together)
Grill for 3 1/2 - 4 minutes per side (each side is done when it can be stuck off the bottom of the pan easily), then grill the other side. Grill for 1 minute and sprinkle with freshly ground pepper.
Add the wine and then immediately add the lemon juice, olive oil, and onion. Lower the heat, cover the pan and cook for a further 5 minutes.
Remove the lid, turn up the heat again, add salt and cook for a further two minutes, until most of the liquid is gone. Remove from the heat and serve immediately.