I made this payasam on Varalakshmi Nonbu. Here is the recipe I followed to make this recipe. I learned this from my MIL.
Almonds - 1/4 cup
Cashews - little less than 1/4 cup
Milk - 2 cups
Water - 1 cup
Sugar - 2 1/2 cups (acc to taste)
Cardamom powder - a pinch
Pachakarpooram - a pinch
Cashews - for garnishing
Soak almonds and cahsews for half an hour in water (or we skip this by microwaving both for 3 minutes). Peel off the skin from almonds. Grind almonds and cashews into a fine paste. what I did was, i just added the grounded paste, milk and water and pressure cooked everything under low flame upto 2 whistles. When pressure is released, open the cooker, add sugar, cardamom powder and pachakarpooram and let it boil for another 15 mts. in low flame. Fry cashews to golden brown and pour it on top of payasam.