Mishti doi

Step 1: Bring 4 ¼ cups full-fat milk to a boil in a heavy, wide pan, then simmer over a medium-low heat for 20 minutes, stirring and scraping the bottom often, until reduced to about 650 ml and slightly thickened.

Step 2: Meanwhile put 2 ⅛ oz sugar and 2 tbsp water in a small pan over a medium heat. Let it melt and bubble without stirring, swirling the pan, until it turns a deep amber caramel, about 4–5 minutes. Watch closely; it goes from golden to burnt in seconds.

Step 3: Take the caramel off the heat and carefully pour in a ladle of the hot milk (it will hiss and seize), then stir over a low heat until the caramel dissolves. Pour it back into the milk with the rest of the 3 ½ oz sugar and 1 pinch ground cardamom if using, and stir until smooth and toffee-coloured.

Step 4: Let the milk cool to about 104°F, warm but comfortable to touch. Whisk 3 tbsp plain live yogurt in a bowl with a ladle of the milk until smooth, then stir it back into the pan.

Step 5: Pour into 6 clay pots or small bowls, cover and leave undisturbed in a warm place (an oven with only the light on is ideal) for 8–10 hours, until set and a spoon leaves a clean cut. Don't move or stir it while it sets.

Step 6: Refrigerate for at least 2 hours to firm up and develop its flavour. Serve chilled. It keeps for 3–4 days in the fridge.