For the venison stock, place the deer bones and offcuts of deer meat into a large pan (the T-bone steaks will be used later). Add enough cold water to completely cover the pan contents, then add two teaspoons of salt and bring the water to the boil.
Reduce the heat until the mixture is simmering and continue to simmer for 1 hour 30 minutes, skimming the froth from the surface of the water at regular intervals. (NB: You will only need 300ml/10½fl oz of stock for this recipe; any excess can be frozen for future use for up to four months.)
For the juniper sauce, place the shallot, garlic, sugar, white wine, juniper berries, white wine vinegar and thyme into a saucepan and bring the mixture to the boil.
Reduce the heat until the mixture is simmering and continue to simmer for 3-4 minutes, or until the volume of liquid left in the pan has reduced to approximately two tablespoons.
Meanwhile, melt the butter in a separate saucepan over a medium heat. When the butter has melted, add the flour and whisk for 30 seconds until the mixture is well combined as a smooth roux sauce.
With the pan of roux sauce still over the heat, strain the wine reduction through a fine sieve into the pan containing the roux sauce. Pick the juniper berries from the ingredients left in the sieve and add them to the sauce. Keep whisking regularly.
Slowly add the hot venison stock, one ladleful at a time, to the roux sauce mixture, whisking each ladleful until fully incorporated into the roux sauce before adding the next ladleful. Once all of the stock has been added to the roux sauce, continue to cook the sauce gently for 10 minutes, or until it has thickened enough to coat the back of a spoon.
Pour in the cream and increase the temperature until the sauce is just simmering (do not allow it to boil), then remove the pan from the heat and season to taste with salt and freshly ground black pepper. Reheat when needed.
For the venison, preheat the grill to its highest setting. Heat an ovenproof griddle pan over a medium-to-high heat.
Rub the venison chops all over with the olive oil, then season to taste with salt and freshly ground black pepper. When the griddle pan is hot, add the venison chops and sear on both sides for 1-2 minutes, or until browned all over.
Transfer the pan to the grill and continue to cook the venison chops for 4-5 minutes (for medium-rare), or until cooked to your liking.
Just before serving, heat a frying pan over a medium heat, add the spring greens and a tablespoon or two of boiling water, then season, to taste, with salt and freshly ground black pepper. Continue to cook for 1-2 minutes, or until the spring greens are just wilted.
To serve, place one venison chop onto each of four serving plates. Spoon over the juniper sauce. Spoon the wilted spring greens alongside. Sprinkle over the chervil.