In a bowl, empty the packet of Mango flavoured jelly crystals.
Pour 1cup boiling water over jelly crystals. Mix well till all the crystals are dissolved and keep aside.
Now take a trifle bowl, or a plain bowl in which you planning to make trifle. Drain the water from the fruit cocktail and put the drained fruits in the trifle bowl.
Now pour the jelly water over fruits in the bowl. Now keep it in the fridge for sometime till its completely set, which should take around 20 minutes. Now the base layer of trifle is done.
Meanwhile lets prepare our cream, while the jelly sets. For doing this, empty the cream into a separate bowl and beat it on high speed for 5 minutes with the help of electric beater. Now add powdered sugar and vanilla essence and beat again till it forms soft peaks. Keep this in fridge.
Cut swiss roll into not so thin pieces and arrange them in the trifle bowl over the jelly as shown in picture.
Pour the custard over this layer and spread it evenly all around the bowl, to make the middle layer.
Now spread some sliced strawberries and grapes over custard.
Now, spread the beaten cream evenly on top and spread all over. Garnish the top with sliced strawberries, grapes halves, and pomegranate seeds. Trifle is ready. Keep it in the fridge until the time of serving. Serve chilled and enjoy.