Place the venison into a food processor and pulse until finely minced. Add the chopped red onion, chilli flakes, mustard and a few drops of Tabasco sauce, to taste, and pulse again to combine. Transfer to a bowl and chill for 10-15 minutes in the fridge.
Lightly oil the inside of a Martini glass. In a bowl, mix together the red wine vinegar, olive oil and herbs and pour into the glass. Press the chilled venison mixture on top, and invert onto a serving plate. Carefully remove the glass and garnish the tartar pyramid with fresh chives.
