Keep whisking at medium-low heat till the agar agar flakes dissolve. This would take 5-6 minutes. You don't the mixture to boil so just keep it at medium-low heat.
Once everything has dissolved, remove pan from heat. Strain the mixture to get rid of any undissolved agar agar flakes.
Pour the strained mixture into three 8 oz ramekins.
Let the mixture cool down a bit, then cover with cling wrap and refrigerate for 3-4 hours or overnight.
Rose Strawberry Sauce
Once the panna cotta is set, start making the rose strawberry sauce. To a pan add fresh strawberries, rose syrup [I used Rooh Afza] and water.
Cook for 6-7 minutes or till strawberries are soft and mixture becomes syrupy.
Remove pan from heat and blend using a blender.
You will get a nice thick sauce. At this point you can adjust the consistency of the sauce and adjust sweetness to taste.
Unmold and serve
To unmold the panna cotta run a paring knife around the edges.
Take a jar/bowl full of hot water and submerge the lower end of the ramekin into that hot water for 10-15 seconds.
Take the serving plate and flip the ramekin on top it. The panna cotta should come out easily.
Spread the prepared sauce all around the panna cotta. Garnish with strawberry, rose petals and chopped pistachios. Serve immediately.