Chop the pineapple pieces in small pieces,Add the spices and chopped mint leaves
Add coconut milk to the pineapple pieces,Mix the coconut milk with spices and marinate the pineapple.Keep it in the fridge for 4 hours/overnight.
Heat a pan/instant pot with heavy bottom and add 2-3 tbsp. oil. Add the whole spices with cumin seeds.Add Onion with little salt.let it cook on medium flame until golden brown.
Add the marinated pineapple pieces. Cook for 10 mins. Now, add the chopped coriander and mint.
Meanwhile, heat a pot with good 5-6 cups of water and salt. Once its is boiling, add rice and let it cook for 7-8 minutes(or until its around 70% cooked).Once the pineapple is partially cooked(70%), start taking out the rice and stack it in the biryani pan.
Spread the saffron mix using a spoon on top of the rice.
Add fried onions on top.Cover the instant pot and use the slow cook option on 'Low' mode for 15 minutes.Open the lid after 15 minutes and serve Biryani.
In case you are using a pot (not an instant pot),cover and cook on the lowest flame for 5 mins and then move the pan to cook at different places for 5 minutes at least 2-3 times i.e cook for 15-20 minutes at lowest flames, changing the position every 5 minutes. Turn off the heat, let the pan be covered for 15 minutes. Remove the lid and slowly mix the rice and pineapple pieces, serve warm.