Peel and finely chop the onion. Scoop half into a bowl. Peel and grate 1 garlic clove into the bowl. Halve the chilli. Finely chop it (flicking out the seeds and white bits for less heat). Add to the
bowl. Stir in 1 tsp turmeric.
Add the venison mince to the bowl. Season with a little salt and pepper and use your hands to mix everything together. Shape the mixture into little balls (koftas) about the size of a walnut and pop on a plate. Cover with cling film and chill in the freezer for 10 mins.
Measure 1 tsp each of the fennel, cumin and coriander seeds into into a dry deep frying pan (that has a lid) and toast for 2 mins till they smell aromatic. Tip the seeds into a spice or coffee grinder and grind, or tip into a bowl and grind with the bottom of a jam jar.
Peel and grate or crush the remaining garlic clove. Put the frying pan back on the heat and warm for 1-2 mins. Add 1 tbsp oil and the koftas. Fry over a medium heat for 5 mins till they're browned all over. Add the onion and season. Cook and stir for 3 mins.
Add the garlic, ground spices and another 1 tsp turmeric to the pan. Add 1 tsp garam masala. Cook and stir for 1 min. Tip in the tin of tomatoes. Shake the tin of coconut milk a few times before opening, then pour into the pan. Cover and simmer for 20 mins till the koftas are cooked through.
While the koftas simmer, sift the plain flour into a bowl. Add 1 tsp baking powder and a pinch of salt. Tip in the pot of yogurt and stir together to make a soft dough. Turn the dough out onto your work surface. Knead for a few mins, then divide into 2 balls.
Pat the dough into 2 flat rounds. Sprinkle another 1 tsp each fennel, cumin and coriander seeds onto the naans and press them in. Warm a separate frying pan for 2 mins. Lay 1 naan in the pan. Fry for 4-6 mins till golden underneath, then flip and fry for 4-6 mins more. Slide onto a plate. Repeat with the second naan.
Taste the kofta sauce and season. Add the spinach and stir for 1-2 mins to wilt it. Spoon the venison koftas into warm bowls and serve with the naan breads.