For the lemon beurre blanc:
Gently reduce the essence of lemon, orange, and sugar by half. Thereupon, incorporate the butter, whisking to form a sublime emulsion.

For the honeyed gelato:
Craft an exquisite crème anglaise with the designated ingredients. Pour the creation into the Pacojet receptacle and surrender it to the freezer at -28°C.

For the final assembly:
Cook the delicate tagliolini for 2 minutes in boiling salted water. Continue to coax their cooking directly within the beurre blanc for another 2 minutes. Nest the pasta elegantly upon the plate, and caramelize the strands with demerara sugar using a torch. Adorn with orange zest and gently nestle a quenelle of honey gelato. Warm the Grand Marnier in a small vessel until it boils, then ignite, serving the dish flambé at the table to the delight of the guests.