First blanch the almonds. Soak them overnight or soak in hot water for 15-30 minutes. Then peel the skin.
Transfer the almonds to a blender along with all ingredients for Thandai paste and make a fine paste.
Add milk as needed to make a smooth paste or syrup.
Add milk to a heavy bottom pan on medium-high heat, and bring to a gentle boil. Add saffron strands to the milk, while it is heating.
Reduce the heat to low, then mix in the thandai paste and sugar. Then add in the rose water. Use a whisk to mix the thandai with the milk. Take off heat.
Let this rest for at least 30 minutes or you can let it cool, and refrigerate it overnight. This helps for the milk to soak in all wonderful flavors.
Strain the thandai. Make sure to take out all the milk from the sieve by pressing the remains.