Toast all the spices in a dry pan. Add them to a spice grinder and mix with salt.
Preheat oven to 220 degrees Fahrenheit
Season oxtails in oxtail spice. Heat olive oil in a large pot over medium-high heat. Add the oxtails and sear completely. Add the remaining ingredients to the pot, and mix well. Cover the pot and place in the oven for 8 hours. Remove from the oven and allow to cool.
Place the meat in a food processor with ⅓ cup of cooking jus and shred. In a large saute pan cook the onion in 2 tablespoons of buttermilk until just caramelized. Fold into the meat mixture.
Add the dry ingredients into a bowl and mix well. Combine eggs cream and milk in a separate bowl. Pour the liquid mixture into a well created in the dry ingredients and mix well and fold until a dough forms. Wrap in plastic and refrigerate overnight.
Roll out dough in a pasta machine into a thin long sheet. Pipe the filling onto the pasta and shape.
Drop the pasta in boiling water and cook until they start to float. Remove and cook in browned butter, oxtail stock and lemon juice. Garnish with fine herbs, sour cream and grilled blackberries. Season with sea salt and lemon zest.