Black Pudding

• 4 cups fresh pig's blood
• 2 1/2 teaspoons salt
• 1 1/2 cups steel-cut (pinhead) oatmeal
• 2 cups finely diced pork fat (or beef suet), finely chopped
• 1 large yellow onion, finely chopped
• 1 cup milk
• 1 1/2 teaspoons freshly ground black pepper
• 1 teaspoon ground allspice