• Pre-heat oven to 425 degrees.
• In a large bowl, whisk together flour, cornmeal, sugar, baking soda, salt, and pepper.
• Using a pastry cutter or your fingers, work butter into flour mixture until chickpea-sized pieces are formed.
• Add buttermilk and stir until just combined.
• Drop ¼-cupfuls of dough into an 8" cast-iron skillet, spaced about 1" apart.
• Bake until biscuits are cooked through, puffed, and golden brown, rotating skillet once, about 12-15 minutes.

Gravy And Assembly:

• While biscuits are baking, heat oil in a medium skillet over medium heat.
• Add chorizo to skillet, breaking up large pieces with a spatula.
• Cook, stirring occasionally, until chorizo is browned and crisp, about 8-10 minutes. Using a slotted spoon, remove chorizo to a small bowl.
• Keeping heat on medium, whisk flour into the drippings in the skillet.
• Continuously whisk until roux is smooth and turning a light golden brown.
• Gradually pour in milk, whisking until incorporated.
• Reduce heat to medium-low and continue to whisk constantly, until gravy is thickened, 5-8 minutes.
• Stir half the chorizo into the gravy and season with salt, pepper, and hot sauce.
• While biscuits are still hot, spoon gravy over them. Top with avocado, scallions, radishes, cotija cheese, hot sauce, and cilantro. Sprinkle remaining chorizo on top, as well.