Gather the Spices & Nuts: In a bowl, add your cashews, pistachios, green cardamoms, nutmeg, fennel seeds, mace, dried rose petals, poppy seeds, and black peppercorns.
Soak the Mixture: Pour completely boiling hot water over these dry ingredients. Cover and let them soak for 1 hour. (Note: If you have time, you can soak them in normal water for 2-3 hours or overnight.)
Prepare the Almonds: Soak the almonds separately. You can choose to peel the skin off or leave it on before blending.
Blend into a Paste: Once soaked, transfer the nuts, spices, almonds, and sugar into a mixer grinder. Blend everything until it forms a thick, smooth Thandai paste.
Prepare the Milk: Take 1 litre of full-fat milk that has been boiled and completely chilled in the fridge. Full-fat milk gives the drink a rich and creamy texture.
Add Saffron: Add the saffron strands (previously soaked in a little milk) into the chilled milk.
Mix the Thandai: Add 2 to 3 large spoonfuls of your freshly ground Thandai paste into the chilled milk. (Note: The amount of paste made is enough to flavour up to 3 litres of milk!)
Final Touch: Stir well, add a splash of fresh rose petal water, and serve chilled. You can add ice cubes if you like it extra cold.