This Chocolate Pistachio Dome with Almond and Pistachio Nougatine is inspired by the elegant Chocolate Journeys desserts served onboard Princess Cruises. It features creamy chocolate mousse dome filled with pistachio crème mousseline. The dome sits on a vanilla sable with a layer of almond pistachio nougatine in between. A mirror glaze is poured over the tops of each dome for an exquisite presentation. This recipe is time-consuming and requires a day of prep before the domes can be fully assembled but the effort is so worth it!
Heat the milk and vanilla over medium heat just until it begins to boil. Meanwhile, mix the sugar, egg yolk, and flour together to form a smooth paste. Slowly pour the milk into the paste while whisking continuously. Return the mixture to the pot and cook over medium-low heat, whisking continuously, until thickened enough to heavily coat the back of a spoon. Remove from heat and strain through a fine mesh sieve. Cover with plastic, making sure the plastic is touching the surface to prevent a skin from forming. Refrigerate until set, about 2 hours.
With an electric mixer, beat the chilled pastry cream and butter together until smooth. Add the almond extract and a couple drops of green food coloring. Beat until well combined.
Pipe the mousseline into 24 .95-inch dome molds. Place in the freezer to set.
Make the vanilla sable
Beat the butter, both sugars, and salt with an electric mixer on medium speed until smooth. Beat in the egg yolk and vanilla. Add the flour and gently mix on low until well combined.
Turn the dough out onto the counter and shape it into a disk. Gently roll the dough into a 1/4 inch thickness between 2 pieces of parchment paper. Slide the parchment paper with dough in between onto a baking sheet and freeze for at least 1 hour.
Preheat the oven to 350°F. Cut out the dough with a 1 and ½ inch round cookie cutter. You need 12 circles of dough. Bake until dry to the touch, about 8-10 minutes. Cool completely.
Make the pistachio almond nougatine
Preheat the oven to 325°F.
In a medium pot, melt the butter and corn syrup over medium heat. Stir in the confectioners' sugar and pectin. Cook until the mixture reaches a full boil. Stir in the pistachios and almonds. Spread the mixture onto a parchment lined baking sheet and bake for 10-15 minutes, until golden brown. Cool completely. Process in a food processor until finely ground.
Make the chocolate mousse
Whip 1 cup of heavy cream to soft peaks. Bring the milk and remaining cream to just to a boil over medium heat. Meanwhile, beat the sugar and egg yolks until smooth. Slowly pour the hot milk into the egg yolk mixture while whisking continuously. Return the mixture to the pot and cook over medium-low heat, while whisking, until thick enough to coat the back of a spoon. Strain through a fine mesh sieve over the chocolate. Mix until chocolate is fully melted. Gently fold in the whipped cream until fully incorporated.
Pipe the mousse into 3-ounce dome molds. Use the back of a spoon to level the mousse inside the molds. Place in the freezer for 20 minutes.
Assemble the domes
Unmold the pistachio creme mousseline and press one into each chocolate mousse dome. Press it until the base of the pistachio creme is flush with the base of the chocolate mousse. Sprinkle ½ to 1 teaspoon of almond pistachio nougatine over the pistachio creme mousseline. Place one vanilla sable over the base of the dome so it sits flush with the mold. Press it gently to make sure it's in contact with the chocolate mousse. Freeze for at least 2 hours or overnight.
Make the chocolate glaze
Combine ¼ cup water and gelatin in a small bowl. Stir until well mixed. Let sit for 5 minutes.
Heat the remaining water, sugar, and sweetened condensed milk in a small saucepan over medium heat just until it begins to boil. Turn off the heat. Stir in the vanilla and gelatin until fully dissolved. Pour over the chocolate and let it sit for 5 minutes until chocolate is fully melted.
Using an immersion blender, blend until very smooth. Take care not to introduce too many air bubbles. Transfer the glaze to a medium bowl set over ice. Stir frequently until the mixture cools to 75°F, about 10 minutes. Strain the chocolate glaze through a fine-mesh sieve into a large pitcher or measuring cup with a pour spout.
Unmold the assembled chocolate domes and arrange them on a wire rack set over a large baking pan. Pour the glaze evenly over each dome. Place the baking sheet with domes in the refrigerator for 15 minutes.
Using a spatula, gently lift the dome off the wire rack and set it on a dessert plate. Press finely ground pistachios or leftover nougatine around the base of the dome. Top with whipped cream and whole pistachios.
Domes are best served shortly after glazing. The glaze will turn gummy if left in the refrigerator for more than 30 minutes.
Notes
Pistachio extract: I haven't found a good pistachio extract. The ones I've tried taste like almond extract. You're welcome to try the one linked below or simply use pure almond extract.
The pistachio creme mousseline yields enough for 24 chocolate pistachio domes. I couldn't reduce the pastry cream more than I did without the risk of burning it during the cooking process. Once the mousseline has been frozen into molds you can transfer the leftovers to a zip-top freezer bag and freeze them for up to 1 month. Use them the next time you make this recipe.
There will also be leftover almond pistachio nougatine. Use it to garnish the domes or save it and sprinkle it over vanilla ice cream. Store it in a zip-top freezer bag in the freezer for up to 2 months.