Mix grated potato and cornflour in a bowl, season, and shape into three rounds.
Heat vegetable oil in a pan and fry potato cakes for two minutes per side until golden.
Sauté garlic and shallot in olive oil for two minutes until softened.
Add red wine and brandy, then simmer until the liquid reduces by half.
Stir in chervil, season with salt and pepper, and set the jus aside.
Heat a griddle pan, rub venison with olive oil, and season well.
Grill the steak for two minutes per side and rest for 2-3 minutes.
Serve sliced steak over latkes and green beans, finished with the shallot jus.