Banana cocoa slice ~ peanut pastry ~ yoghurt and lime sorbet by Paul Ainsworth

Ingredients

• 250 gall-butter puff pastry
• 100 gcaster sugar
• 100 g70% dark chocolate
• 50 gcaster sugar
• 50 gegg yolks
• 175 gdouble cream
• 25 gwhole milk
• 225 gGreek yoghurt
• 55 gstock syrup
• 20 gsorbet stabiliser
• 5 gglycerine
• 60 gsalted butter
• 25 gglucose
• 25 gwhole milk
• 75 gcrushed peanuts
• 75 gcaster sugar
• 20 gwater
• 4straight, ripe bananas
• 100 gdemerara sugar
• 1bright green lime, finely zested and frozen

Instructions

1. 1

   Freeze the sorbet

   Blend the Greek yoghurt, stock syrup, sorbet stabiliser and glycerine until smooth. Freeze for 10 hours, then pacotize just before serving.

2. 2

   Make the nougatine

   Cook the caster sugar and 20 g water over medium heat until the syrup reaches 118°C. Meanwhile, combine the salted butter, glucose and milk. When the sugar syrup reaches 110°C, bring the butter mixture to the boil and add the crushed peanuts. Once the sugar syrup reaches soft-ball stage, add it to the peanut mixture and stir until combined. Transfer to a container and chill.

3. 3

   Bake the nougatine

   When the mixture is cold and set, take it out of the fridge and place it on a large tray lined with greaseproof paper. Let it come to room temperature, spread it evenly to 2 mm thick and bake at 180°C for 10 minutes. Rotate the tray and check every 2 minutes until amber. Keeping it on the paper, move it to a chopping board, cut it in half horizontally, then cut rectangles measuring 12 cm by 3 cm. If it becomes too brittle to handle, return it to the oven for 1 minute at a time. Make extra pieces as they are fragile; store them in an airtight container until needed.

4. 4

   Bake the pastry

   Roll the puff pastry to 2 mm thick and sprinkle it evenly with a thin layer of icing sugar. Sandwich it between sheets of greaseproof paper and large trays. Bake at 180°C for 10 minutes, rotate the tray, then check after 5 minutes and every few minutes thereafter, rotating as needed, until deep golden brown. Cool and cut into 12 cm by 3 cm rectangles; allow two per portion and keep spare pieces.

5. 5

   Prepare the mousse

   Melt the chocolate over a bain-marie. Whisk the milk and cream to stiff peaks. Meanwhile, heat the sugar and water in a pan over medium heat; the method gives 110°C for this syrup, then refers to soft-ball stage at 118°C. Whisk the egg yolks at high speed in a stand mixer. When the syrup reaches soft-ball stage, pour it down the side of the bowl without letting it touch the whisk. Continue whisking to sabayon stage, then add the melted chocolate. Whisk on low until combined and the mixture is at body temperature. Fold in the cream in three additions, transfer to a piping bag and chill for 2–3 hours.

6. 6

   Assemble and serve

   Trim each banana to 10 cm and cut it into 2 mm rounds, keeping the slices in the banana's original shape. Press them gently so they overlap and check that the banana is no longer than the pastry layers. Carefully transfer it to a stainless-steel tray, sprinkle with demerara sugar and use a blowtorch to caramelise it to amber without burning; repeat to make a thin crisp layer. Pipe the mousse in a tight zigzag on a piece of puff pastry to support the layers. Put a small dot of mousse just off the centre of each plate and set the pastry and mousse on it to hold it in place. Add another pastry layer, then the caramelised banana and the peanut nougatine. Keep the layers straight. Place a quenelle of yoghurt sorbet just off-centre on the other side of the plate, finish with a pinch of frozen lime zest and serve.

What is a banana cocoa slice?

It is a composed plated dessert rather than a traditional slice: crisp pastry and chocolate mousse are layered with caramelised banana and a brittle peanut topping, then served with tangy yoghurt sorbet. The title suggests the combination of banana, cocoa and peanut, while lime adds a bright contrast.

The recipe is credited to Paul Ainsworth. Its restaurant-style character comes from assembling separate components at the last moment, so each keeps its own texture.

Nutrition and macros by portion

The nutrition label shows one serving as written: 1210 calories, 19g protein, 150g carbs, 72g fat.

The pastry, sugars and banana provide most of the carbohydrates, while the butter, cream, chocolate and peanuts contribute much of the fat. Chocolate, egg yolks, yoghurt and peanuts also contribute protein. For a more balanced plate, serve a modest portion after a meal with fruit or a less rich dessert alongside it.

The components to prepare ahead

Sorbet: blend the yoghurt mixture until completely smooth before freezing. The recipe calls for pacotizing just before serving, so allow for the stated 10-hour freeze.

Mousse: chill it in the piping bag for 2–3 hours, which makes it easier to pipe into an even, stable layer.

Nougatine: it can be kept in an airtight container once cut. Make spare shards because thin caramelised pieces can snap during handling.

Getting an even pastry bake

Thin pastry: roll it to 2 mm and keep it between greaseproof paper and trays as directed. This helps keep the layers flat as they bake.

Colour: start checking after the initial 10 minutes at 180°C, then rotate and check every few minutes. Aim for deep golden brown, and let the pastry cool before cutting so the rectangles are easier to handle.

Working with the nougatine

Syrup: watch the thermometer closely as the sugar mixture approaches 118°C. The butter, glucose and milk mixture needs to be brought to the boil when the sugar syrup reaches 110°C, as the method specifies.

Cutting: spread the cooled mixture to 2 mm and cut it while it is workable. If it hardens too much, warm it in the oven for 1 minute at a time, checking as you go.

How to judge the mousse

Whipped cream: take it to stiff peaks before folding, but handle it gently when combining it with the chocolate and sabayon. Add it in three batches to help keep the mixture smooth.

Temperature: the method says to mix the chocolate into the sabayon and whisk until the mixture reaches body temperature before folding in the cream. This helps the components combine without losing the mousse's light texture.

Caramelising the banana

Shape: slice the banana to 2 mm while keeping the rounds arranged in its original form, then press them gently so they overlap. Trim the arrangement to the length of the pastry.

Finish: use the blowtorch to turn the demerara sugar amber and crisp, taking care not to burn it. Repeat the process for the second thin layer, as the recipe directs.

Serving the finished dessert

Assembly: pipe mousse in a tight zigzag on the pastry so it supports the layers. A small extra dot of mousse on the plate helps keep the stack in place.

Contrast: serve the yoghurt sorbet beside the pastry stack and add the frozen lime zest just before serving. The cold, tangy sorbet and citrus lift the rich chocolate, pastry and peanut.

Recipe notes & tips

• Weigh and organise the components before starting, as the dessert uses several separate preparations.
• Use a sugar thermometer for the syrup stages and keep the pan handle turned away from the edge of the hob.
• Cut extra pastry and nougatine rectangles to allow for breakages during assembly.
• Let the baked pastry cool completely before cutting it into neat rectangles.
• Assemble close to serving time so the pastry and nougatine stay crisp.
• Keep the lime zest frozen until the final garnish.

Variations

• More lime: add a little extra finely grated lime zest to the yoghurt sorbet mixture.
• Different nuts: replace the peanuts with crushed hazelnuts for a different praline-like flavour.
• Dark chocolate: use a higher-cocoa dark chocolate for a more intense mousse.
• No blowtorch: caramelise the banana under a hot grill, watching it closely so it does not burn.
• Simpler plating: serve the mousse, pastry and banana as separate components with the nougatine broken into shards.

Common mistakes to avoid

• Soft pastry: bake until deep golden brown and cool it fully before assembly.
• Burnt nougatine: rotate the tray and check every 2 minutes once the first 10 minutes have passed.
• Brittle nougatine: warm it in the oven for 1 minute at a time until it is workable.
• Runny mousse: chill it in the piping bag for the full 2–3 hours before assembling.
• Burnt banana sugar: move the blowtorch continuously and stop when the sugar turns amber.
• Unstable layers: pipe the mousse in a tight zigzag and use a small dot of mousse to anchor the stack to the plate.

How to store

Store the sorbet in the freezer and keep the nougatine pieces in an airtight container. The mousse can be chilled in its piping bag, but assemble the dessert just before serving to preserve the pastry's crispness; leftover assembled portions are best eaten straight away.

Frequently asked questions