In a large bowl, wish together milk and egg. Add the corn, sausage, scallions, cheese and vinegar and stir to combine. Add spices and stir. Sprinkle on the cornmeal and flour and stir until well combined. Coat the bottom of a cast iron skillet with oil and heat over medium heat. Use a 1⁄4 cup measuring cup or spoon to scoop the batter into the pan. Cook for 2-3 minutes until golden brown. Flip and repeat until golden brown. Work in batches and add more oil if needed. Garnish with scallion and sour cream if desired.