Heat oven to 450°F. Line two large baking sheets with parchment paper. Stir together the flour, cornmeal, baking powder, baking soda, and smoked Spanish paprika in a medium-sized bowl. Cut in the cold butter and scallions with a pastry blender, your fingers, or two knives until the mixture resembles very course crumbs. Fold the cheddar and chorizo sausage into the butter and flour mixture.In a separate, small bowl, mix together the sour cream and milk. Add to the flour and butter mixture. Stir only until combined. Turn the dough out onto a slightly floured surface and shape into a disk about one inch thick. Cut the biscuits into the desired shape (I used a 1-inch, round biscuit cutter) and place onto the prepared pan.In a small bowl, combine the egg yolk and 1 tablespoon water. Brush the biscuits with the egg wash and top each biscuit with 1 tablespoon shredded cheddar. Bake for 10–12 minutes, or until golden brown. Let cool on a wire rack. Enjoy.*TIP: These biscuits, unlike a typical batch of biscuits, are even better the next day. They are perfect companions for a spicy batch of chili or can be served as appetizers if made in miniature form.Heat oven to 450°F. Line two large baking sheets with parchment paper. Stir together the flour, cornmeal, baking powder, baking soda, and smoked Spanish paprika in a medium-sized bowl. Cut in the cold butter and scallions with a pastry blender, your fingers, or two knives until the mixture resembles very course crumbs. Fold the cheddar and chorizo sausage into the butter and flour mixture.In a separate, small bowl, mix together the sour cream and milk. Add to the flour and butter mixture. Stir only until combined. Turn the dough out onto a slightly floured surface and shape into a disk about one inch thick. Cut the biscuits into the desired shape (I used a 1-inch, round biscuit cutter) and place onto the prepared pan.In a small bowl, combine the egg yolk and 1 tablespoon water. Brush the biscuits with the egg wash and top each biscuit with 1 tablespoon shredded cheddar. Bake for 10–12 minutes, or until golden brown. Let cool on a wire rack. Enjoy.*TIP: These biscuits, unlike a typical batch of biscuits, are even better the next day. They are perfect companions for a spicy batch of chili or can be served as appetizers if made in miniature form.