Preheat the oven to <temperature>175<unit>°C</unit></temperature>

Add <quantity>350<unit>g</unit></quantity> of all-purpose flour and <quantity>70<unit>g</unit></quantity> of white sugar to a large bowl

Add <quantity>200<unit>g</unit></quantity> of cold butter. Mix by hand quickly to incorporate until you obtain a coarse, sandy texture

Add <quantity>2</quantity> egg yolks and mix by hand until the dough comes together

Tap the dough to form a smooth ball

Spread the dough in an even layer in a <quantity>26<unit>cm</unit></quantity> tart pan and trim the edges

Puncture the dough with a fork

Bake the crust for 12m until golden. Remove from heat and let it cool before filling

Add <quantity>200<unit>g</unit></quantity> of sugar to a saucepan

Add <quantity>250<unit>ml</unit></quantity> of sea buckthorn juice

Add <quantity>2</quantity> egg yolks

Add <quantity>1</quantity> egg

Place over low heat and whisk for 5-8m until the mixture starts to thicken

Remove from heat and add <quantity>1</quantity> leaf of hydrated gelatin that has been squeezed dry. Whisk until dissolved

Add <quantity>200<unit>g</unit></quantity> of butter, a few chunks at a time, whisking well after each addition. Keep whisking for 3-5m to slightly cool down

Pour the sea buckthorn mixture over the tart crust and tap it lightly on the counter to evenly spread it and remove air bubbles

Place the tart in the refrigerator for 3h to firm

Place a large bowl over a pot with water to make a water bath. Make sure the bowl doesn't touch the water and bring it to a simmer over low heat

Add <quantity>100<unit>g</unit></quantity> of egg whites to the bowl

Add <quantity>250<unit>g</unit></quantity> of powdered sugar and whisk until the mixture reaches <temperature>65<unit>°C</unit></temperature>. Remove from the heat

Beat with a mixer on high speed until fluffy and completely cool. The Swiss meringue is ready

Remove the tart from the refrigerator and evenly spread the Swiss Meringue on top

Toast the meringue with a blow torch. The sea buckthorn meringue tart is ready

Enjoy this as the perfect end to a meal!