Remove the skin and membrane on the venison, then cut in slices roughly 1 cm thick. Place the venison between sheets of cling film and beat flat with a meat hammer or rolling pin.
Heat the oil in a heavy-bottomed pan, add the fennel and fenugreek seeds, bay leaves, cinnamon, star anise and cardamom, allow to crackle, then add the onions and fry until a pale golden brown.
Add the ginger and garlic and cook for a minute or two. Add the venison slices, and brown on both sides, then add the ground spices, plus salt to taste, and cook for 2-3 minutes.
Once the spices have coated the venison, pour in 230 ml (8 fl oz) water, lower the heat and simmer for 7-8 minutes. Add the tomato purée and cook for a further minute. Sprinkle the chopped coriander on top and remove from the heat.
Meanwhile, heat the oil in a separate frying pan, then fry the potato juliennes until pale gold and crisp. Drain on kitchen paper and lightly salt. Serve the venison topped with the straw potatoes.