Pumpkin and Chipotle Corn Chowder

Name: Pumpkin and Chipotle Corn Chowder
Ingredients: 3 tablespoons butter ( or vegetable oil); 7 cups Pumpkin (peeled and cut into 1-inch cubes); 1 large onion (diced); 3 tablespoons all-purpose flour; 1 quart reduced-sodium chicken stock; 2 chipotle peppers in adobo sauce (finely chopped); 2 cups corn kernels (frozen); 1/2 cup heavy cream; 5 thyme sprigs (or 1 tablespoon dried thyme, or to taste); salt and freshly ground black pepper; 1 small bunch cilantro (stems removed and leaves roughly chopped)