For the Coffee-roasted Beets:
Preheat oven to 325°F. Mix the salt, coffee, flour, and egg whites together until homogenous. Cover the beets with the paste. Roast until tender. When cool, rub off the crust skin with a towel and cool beets. Slice into 1/4–inch rounds.
For the Panna Cotta:
Cook the white chocolate sous vide at 90°C for 12 hours to caramelize. Bring the milk and cream to a boil. Whisk in sugar and agar agar, and emulsify with the chocolate. Pour the mixture into 2 half hotel pans greased with non-stick pan spray. When firm, cut with a round cutter.
For the Tuile:
Put the sugar, milk powder, vanilla paste, and water in a blender and mix on medium speed. Pour the carrageenan and guar gum into the vortex. Blend on high until the temperature reaches 100°C. Pour into a stand mixer and mix until cool. Spread onto greased parchment paper and dehydrator overnight.
For the Sorbet:
Bring the glucose, sugar, and milk to a boil. Chill over an ice bath. Blend in the buttermilk with a hand blender, chill overnight, and churn in an ice cream machine according to manufacturer's instructions.
For the Sauce:
Bring the lemon juice and honey to a boil. Blend in the sugar and the agar agar. Chill to set, then purée into a thick sauce. Adjust consistency with the xanthan gum if necessary.
For the Streusel:
Preheat oven to 300°F. Cream the sugar and 110 grams butter together in a stand mixer. Beat in the egg and vanilla extract. Add in the flour, baking soda, salt, oats, and ras el hanout. Spread out onto a baking sheet, and bake at until dry. Increase oven temperature to 325°F. Melt the remaining 50 grams of butter. Crumble and add the milk powder, corn starch, white couverture, and melted butter. Bake at 5 minutes, stirring periodically, until toasted.
To Assemble and Serve:
Plate the Coffee-roasted Beets and Panna Cotta. Drizzle with Honey-Lemon Sauce and dot the plate with Streusel. Quenelle the Buttermilk Sorbet on one side, top with Tuile, and garnish with olive oil.