For the spice blend: Grind the coriander seeds, fennel seeds, ginger powder, annatto seeds, pomegranate powder, nutmeg, bay leaves, cloves, star anise, cinnamon and mace in a spice grinder until finely ground. Store in an airtight container in a cool, dark place.
For the biscuits: Preheat the oven to 400 degrees F. Sift together the flour, 1 teaspoon of the spice blend, the baking powder, sugar, salt and baking soda into a stainless-steel bowl and chill in the freezer until cold. Cut the butter into the flour mixture using a dough cutter, large fork or in the bowl of a food processor, being careful not to overwork the dough. The butter should remain visible in the dough.
Pour the mixture out onto the counter and make a well in the middle. Pour three-quarters of the buttermilk into the well and quickly incorporate it. Add more liquid if needed until the dough holds its shape.
Press out 3/4-inch thick and cut into desired shapes. Bake for 10 minutes, reduce the heat to 350 degrees F, and then bake until golden brown and light to the touch.
For the foam: Whip the cream and sugar to firm peaks, and then fold in the sour cream, lemon zest, powdered vanilla and salt. Refrigerate until ready to use.
For the creme anglaise: Scrape the vanilla beans well and place the seeds, pods, 1/2 cup sugar, the white pepper and salt in a pot with the milk. Bring to a boil, and then remove from the heat. Let infuse for 10 to 15 minutes. Beat the yolks with the remaining sugar. Bring the milk back to a simmer. Add a ladle of milk to the yolks, whisk, and then pour into the milk. Cook, stirring, until the mixture is thick enough to coat a spoon.
Remove from the heat and pour in the cream to stop the cooking. Pour through a fine mesh sieve, pressing against the solids to get as much liquid through as possible. Pour into a bowl set over ice water to chill.
For assembly: Cook the sausage in a pan until the fat has been rendered out. Add the syrup and cook until thick and absorbed.
Cut each biscuit in half horizontally. Top with a scoop of ice cream, drizzle with creme anglaise and sprinkle with the sausage. Spoon on some foam and top with remaining biscuit halves. Garnish with sage.
If you do not have a spice blender, a coffee grinder works fine for the spice blend. Grate the chilled butter on a box grater just before needed to get it into small pieces. You may substitute milk with a little vinegar mixed in for buttermilk.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.