This trifle is based on the classic preparation with fruit, sponge, liquer, custard and a final topping of whipped cream.  Rory says in How to Cook Well with Rory O'Connell on RTÉ One, that he uses the recipe as a trifle master plan throughout the year!

Rory: "Rhubarb is the first fruit to be used. It will be followed by gooseberries, then into the strawberries, followed by currants and so on, so it is immensely useful. The great thing about a trifle is that it can be prepared ahead, ideally the day before and the finishing touch of cream and an appropriate garnish is quickly and easily achieved. 

"The custard, also referred to as pastry cream, is lightened up by the addition of two of the whisked up egg whites, thereby adding a volume of air and achieving a rather more foamy result. 
When assembling a trifle, the balance of the assembly of the ingredients is important so as to end up with a consistency that is neither to wet nor too dry. I like to put it together while the custard is still slightly warm as this creates a more sumptuous consistency.

"I like to use a glass bowl for serving the trifle, but in fact the volume of the bowl is much more important than the style of it, as the volume will affect the proportion of the finished dish."

Ingredients:

  • Use deep pinky red and firm stalks of rhubarb here to ensure a rich flavour of the fruit. 
  • Try to ensure that the almonds and pistachios are as fresh as possible. Like all nuts they can be dull and even rancid when old.
  • 450g pink or bright red rhubarb stalks
  • 175g cater sugar
  • 125ml water
  • 6 tablespoons kirsch (optional)
  • 1 sponge cake

Pastry cream

  • 300ml milk
  • ½ a vanilla pod or 1 teaspoon vanilla extract
  • 3 eggs
  • 110g caster sugar
  • 25g flour

Finishing the trifle

  • 425ml softly whipped cream
  • 50g toasted flaked almonds
  • 30g shelled unsalted pistachios 

Rhubarb

Method:

  1. Begin by cooking the rhubarb. Place the chopped rhubarb, sugar and water in a small stainless steel saucepan and cover. Place on a moderate heat and bring to a simmer. Cook covered until the rhubarb is completely tender and just beginning to collapse. I use a glass saucepan lid or a Pyrex plate for covering the saucepan so I can more easily see what is happening in the saucepan. You don’t really want the rhubarb to collapse to a stringy consistency as the trifle is better to eat if the rhubarb still has some degree of its identity intact. However it is crucial that all of the rhubarb is tender. Allow the rhubarb to cool somewhat while you proceed with the pastry cream.
  2. Meanwhile make the pastry cream. Bring the milk to just below boiling point with the vanilla pod if using or add the vanilla extract later. Allow the heated milk to sit and infuse off the heat.
  3. Separate 2 of the eggs and place the whites in a spotlessly clean bowl for whisking later. 
  4. Put the two egg yolks and the remaining whole egg in a bowl with the caster sugar and whisk until light and fluffy. Gently whisk in the flour until thoroughly mixed in. If you are using a vanilla pod, at this point, split it or cut a tiny piece off one end and squeeze the vanilla seeds into the sugar and egg mixture. If you are using vanilla extract add it now.  
  5. Pour the still warm milk over the mixture and whisk in well to mix. Return the mixture to a clean saucepan and stir it continuously with a combination of a flat bottomed wooden spoon and a whisk. The flat bottomed wooden spoon prevents the custard from sticking to the bottom of the pan and the whisk breaks down any lumps as they form. Allow the mixture to come to a boil and then simmer, still stirring for 2 minutes. This simmering of the custard is vital to get it to thicken properly and to ensure the raw taste of the flour is cooked off the mixture. Remove the custard from the heat, transfer to a clean bowl and allow to cool for 5 minutes. Whisk the egg whites to a stiffish peak and fold into the custard. The result should be an air filled and slightly foamy custard.

Assembling the trifle.

  1. Use a bowl not less than 1 litre and not bigger than 1300ml in volume.
  2. Cut the sponge cake in half horizontally to achieve two neat discs. Place one of the discs, cut side down, in the bottom of your chosen bowl. The shape of your bowl will determine how much you need to manipulate the sponge to make it fit. If it starts to come up the sides of the bowl, that is absolutely fine.
  3. Add the kirsch if using, to the poached rhubarb. Spoon about half of the rhubarb and its juice over the sponge, making sure that the cake is thoroughly moistened. Spoon over half of the pastry cream.
  4. Place the remaining cake, cut side up, on top. Again you may have to bully the sponge in to place. Don’t be afraid to cut off little bits and do a bit of patching if necessary. Spoon over the rest of the rhubarb.
  5. Finish with the remaining pastry cream and smooth off the surface with the back of a spoon. I often get a skewer to the trifle at this stage and prod it a few times, making un-noticeable holes right down to the bottom of the bowl to encourage the juices to moisten the sponge.
  6. Cover the bowl and chill for at least 8 hours or better still over night.

Serving the trifle
Spread the softly whipped cream over the trifle and sprinkle over the cooled toasted almonds and the pistachios.

Trifle Variations:

Rhubarb and Strawberry Trifle

When the cooked rhubarb is nearly cooled, add 250g of sliced or diced ripe fresh strawberries. Assemble the trifle as in the master recipe.

Gooseberry and Elderflower Trifle

Follow the master recipe, replacing the rhubarb with 450g of hard green, topped and tailed gooseberries. Cook the gooseberries in the same way as the rhubarb, adding if possible 3-4 elderflower heads to the pot. Make sure the cooked berries are completely tender and some will have collapsed, but like with the rhubarb, don’t boil away their charm. Remove the by then collapsed elderflower heads from the gooseberries before assembling the trifle. The elderflowers will have given a delicious muscat flavour to the fruit. The kirsch could be replaced with Muscat de Beaumes de Venise dessert wine and you could have the rest of the bottle as a pudding wine when eating the trifle. 

A tasty trifle
 
Summer Berry Trifle

The berries in this lovely fresh tasting trifle are uncooked.
If you had a perfectly ripe peach or two, you could peel, stone and slice them and add to the berries to make up the suggested weight of fruit.
Replace the rhubarb in the master recipe with 450g of mixed summer berries such as strawberries, raspberries, loganberries, tayberries, a few stoned cherries, all coarsely chopped and mixed with 115g of caster sugar. Allow the sugar to dissolve into a juicy syrup on the berries before assembling the trifle. It will take about 30 minutes for that to happen.
The kirsch will be perfect here if you wish to use it.
I sometimes sprinkle whole blueberries on top of the whipped cream before serving this trifle

Apple, Blackberry and Sweet Rose or Lemon Geranium Trifle

This is a lovely autumn version for you to try, or if you have a few blackberries in your freezer, this could also be a good one for the depths of winter.
If you don’t have the geranium leaves, it is still worth making, though the perfumed geranium takes it on to another level.

Replace the rhubarb in the master recipe with 450g of bramley cooking apples, peeled, cored and roughly chopped and 100g of blackberries and cook with the sugar, water and 4 sweet geranium leaves until it collapses to a frothy fluff, stained pink by the berries.
Remove the collapsed geranium leaves before assembling the trifle according to the master recipe. 
Sweet sherry could replace the kirsch here.