TOAST THE HAZELNUT BASE
1. Preheat oven to 350°F (180°C). Spread hazelnuts on a baking sheet and toast for 8–10 minutes, shaking once, until golden and fragrant. Watch carefully — hazelnuts burn quickly once they turn.
2. Let cool for 5 minutes, then roughly chop — a mixture of fine crumbs and larger pieces for textural variety. Toss with melted butter, brown sugar, and salt.
3. Divide the hazelnut mixture among four serving vessels (glasses, ramekins, or shallow bowls, about 200 ml / 7 oz each), pressing gently to create a compact base layer. Set aside.

MAKE THE SALTED CARAMEL
4. Place the ⅓ cup sugar in a heavy-bottomed saucepan over medium heat. Do not stir — let the sugar melt from the edges inward, swirling the pan gently to redistribute. Cook until deep amber colour, about 4–5 minutes. It should smell richly of toffee, not burnt.
5. Immediately remove from heat and carefully pour in about half the cream — the mixture will bubble violently and seize. This is normal. Return to low heat and whisk gently until the caramel dissolves back into the cream. Add remaining cream and milk, whisking until smooth. Bring to just below a simmer.

MAKE THE CRÉMEUX
6. In a separate bowl, whisk the egg yolks with the 2 tablespoons custard sugar until pale and slightly thickened, about 1 minute.
7. TEMPER THE EGGS: Pour about a third of the hot caramel-cream mixture into the yolk mixture in a slow stream, whisking constantly. Pour the tempered mixture back into the saucepan with the remaining caramel cream.
8. COOK THE CUSTARD: Return to medium-low heat and cook, stirring constantly with a spatula, scraping the bottom and corners. The custard is ready at 180°F (82°C) on an instant-read thermometer, or when it coats the back of a spoon thickly enough that a line drawn through it holds its shape (nappe stage). Do not let it boil.
9. EMULSIFY WITH CHOCOLATE: Immediately strain the hot custard through a fine-mesh sieve onto the chopped chocolate. Let sit for 1 minute, then stir gently from the centre outward in small circles until perfectly smooth and glossy. A brief blitz with a stick blender on low speed creates the smoothest emulsion — avoid incorporating air.
10. SEASON BOLDLY: Stir in the flaky sea salt. Taste — the salt should be clearly present, cutting through the chocolate's richness. Add more if needed.
11. SET THE CRÉMEUX: Pour warm crémeux over the hazelnut bases, filling to about three-quarters full. Press cling film directly onto the surface of each to prevent a skin forming. Refrigerate for at least 4 hours, ideally overnight. The set texture should be spoonable and dense but yield softly.

PREPARE THE BOURBON ORANGES
12. SEGMENT THE ORANGES: Cut top and bottom off each orange. Stand on a cut end and carefully cut away all peel and pith. Holding the peeled orange over a bowl, cut between membranes to release individual segments.
13. MAKE THE BOURBON SYRUP: Squeeze remaining juice from membranes into a small saucepan. Add sugar and bring to a gentle simmer, stirring until dissolved. Cook 2–3 minutes until slightly thickened. Remove from heat, stir in bourbon and vanilla.
14. Pour warm syrup over orange segments. Cover and refrigerate for at least 30 minutes or up to 24 hours.

MAKE THE BOURBON CREAM
15. In a chilled bowl, whip cold cream and icing sugar to soft peaks — billowy, not stiff. Fold in the bourbon. The bourbon should be clearly identifiable.
16. Keep refrigerated until plating. Can be made up to 2 hours ahead.

PLATE AND SERVE
17. Remove crémeux from the fridge 5–10 minutes before serving to take the sharp chill off. Peel off cling film.
18. Spoon or quenelle a generous portion of bourbon cream on top of or alongside the crémeux. Arrange 4–5 bourbon orange segments next to or around the crémeux, drizzling bourbon syrup over them. Scatter a few wasabi rocket leaves across the plate. Finish with flaky sea salt on the crémeux surface and, if desired, the lightest drizzle of olive oil.
19. Serve immediately. The crémeux will slowly soften at room temperature, which is desirable — a slightly relaxed crémeux has a more luxurious mouthfeel than a fridge-cold one.