Tie the venison with kitchen string, rub with olive oil, and season with salt and pepper.
Sear the venison in a hot pan until browned on all sides, then add a knob of butter.
Add garlic and half of the thyme to the pan and fry gently for ten minutes.
Rest the meat for five minutes, remove the string, and slice thinly.
Fry the chopped potato and crushed garlic in an ovenproof pan with vegetable oil for five minutes until golden.
Roast the potatoes in the oven for 15 minutes and drain on kitchen paper.
Soften the onion in the venison pan and deglaze with red wine.
Add a splash of boiling water and simmer for 4 minutes until reduced.
Stir in the cream, season the sauce, and serve over the venison and wedges garnished with parsley.