Mexican Street Corn Chowder

Name: Mexican Street Corn Chowder
Ingredients: 1/4 cup unsalted butter; 1 medium onion (- chopped); 1 large jalapeño pepper (- diced); 2 pounds yellow potatoes (- peeled and chopped); 3 cloves garlic (- minced); 1 teaspoon cumin; 2 teaspoons chili powder; 1 teaspoon onion powder; kosher salt and freshly ground black pepper (- to taste); 1/4 cup all-purpose flour; 4 cups chicken broth; 1 teaspoon granulated sugar; 1 ¼ cups heavy cream; 1 ¼ pounds fresh corn kernels (or frozen) (- from about 8 ears); sour cream, cotija cheese, chopped cilantro, jalapeño slices, lime juice (- to serve)