Patisa is a traditional Indian sweet that embodies the rich confectionery heritage of the subcontinent. This beloved dessert is a family favorite at festivals, weddings, and celebrations.
Grease an 8-inch square baking pan and set aside; this will ensure easy removal after setting.
Heat the ghee in a heavy-bottomed pan over medium-low heat. Once melted, add besan and semolina, and roast slowly, stirring constantly to avoid burning, for 20–25 minutes until the raw aroma disappears and the mixture is nutty and golden.
Meanwhile, in a saucepan, bring sugar and water to a boil. Add cardamom powder and lemon juice, then continue boiling until a single-thread sugar syrup forms (about 210–215°F, 99–102°C), testing with your fingers or a spoon.
Reduce the heat under the besan mixture to low, then carefully pour in the hot sugar syrup and milk while stirring vigorously to prevent lumps. The mixture will bubble; keep stirring quickly for even texture.
Continue cooking on low heat until the mixture thickens, starts leaving the sides of the pan, and shows a granular, flaky texture (about 6–8 minutes). Immediately transfer into the prepared pan, spreading evenly with a spatula.
Sprinkle slivered almonds and pistachios on top while warm and gently press them in. Let the Patisa cool completely at room temperature, then cut into squares with a sharp knife and serve.