Put the coconut milk and sugar into a heavy-based saucepan and place over medium-low heat. Stir well to dissolve the sugar, then simmer for 20 minutes, without stirring, until thick – you should have about 1 cup (250 ml).
Meanwhile, sift the chickpea flour straight into a large non-stick frying pan over low heat and add the coconut oil.
Toast the chickpea flour until it starts to tan and begins to smell less beany and more caramelised. When it’s done, tip the chickpea flour out of the pan into a shallow dish, to prevent it from burning in the hot pan.
Sift the chickpea flour into a large bowl, then add the chopped nuts, cardamom and icing sugar to taste, if you have a sweet tooth. When the coconut milk is ready, pass it through the sieve into the bowl and mix everything well.
Grease and line a 20 cm square brownie tin with baking paper, then pour in the burfi mixture. Flatten it by laying a second sheet of baking paper over the top and pressing down with a spatula. Remove the top layer of paper and, using a greased knife or pizza wheel, cut into squares. Top the burfi with more chopped nuts, then let it chill and set in the fridge for 1–2 hours before eating.
Note: You can make a vanilla version of this fudge by using ½ teaspoon vanilla extract instead of the ground cardamom.