Heat 2 tablespoons butter in a medium skillet over medium heat, add onion and cook, stirring occasionally, until softened, about 4 minutes. add chorizo and saute until onion is soft and chorizo is lightly browned, about 4 minutes more. drain the fat and transfer to medium bowl and let cool.
preheat oven to 350 degree oven. bring the water to a boil in a small saucepan. slowly pour in cornmeal, stirring constantly. reduce heat to medium-low and cook, stirring until thickened, 2 minutes. add sausage mixture, stir in corn kernels, salt and the remaining tablespoon butter, and combine well.
Whisk together eggs and cream.stir in sausage mixture until combined well. pour into a buttered 2-quart deep pie plate. bake until set and top is golden brown, about 1 hour. serve hot