In a large pot, brown the chorizo on medium for about 5 minutes, breaking it up with a spoon as it browns. Remove from the pan.Add the onion and jalapeño with a pinch of salt and sauté until soft, 3-4 minutes then add the garlic. Sauté another minute more. Add the butter and the flour and cook for a couple minutes, stirring constantly.Add the corn, broth, potatoes, spices and a good pinch of salt. Bring to a boil then turn down to a simmer. Simmer for about 35 minutes. Taste for seasonings and add more salt if needed. Finally stir in the cream. Garnish with sour cream, cotija cheese and cilantro.