Soak oats in sufficient amount of water for 30 minutes.
Soak almonds and cashews separately for 30 minutes.
After 30 minutes, remove the skin of almonds. If you find it hard to remove the skin, then microwave or boil almonds for 1-2 minutes and then remove the skin.
Add almonds and cashews in a grinder jar after draining all the water.
Make a fine paste out of it.
Then drain oats and add them to the blender.
Blend to fine paste.
Then add sugar and vanilla essence.
Again blend to fine puree. This is oats kulfi base. Keep aside.
Take a mango but do not peel it. Remove the top of the mango by slicing the head. Retain this cap.
Now using a kitchen knife loosened the pulp around the mango seed.
Firmly hold the seed with a tong and rotate it to loosen it further.
Pull the seed out.
Place the mango inside a small cup so that it stands upright.
Remove any pulp from the seed and add it back to the empty mango shell.
Fill the mango cavity shell with the oats kulfi base.
Put the mango cap back and freeze it for 8-10 hours.
Remove and peel the mangoes.
Slice and serve after garnishing with pistachios and saffron and serve immediately.