“Cacio e Pepe” Corn Chowder

Name: “Cacio e Pepe” Corn Chowder
Ingredients: 4 cups fresh corn, cut from 4 large ears, cobs reserved)4; cups chicken broth; 2 cups water; 2 tablespoons olive oil; 4 ounces pancetta, diced; 2 tablespoons butter; 1 cup diced onion; 1/2 cup diced celery; 3 cloves garlic; 1/3 cup all-purpose flour; 3/4 cup whole milk; pinch cayenne pepper, optional; 1/3 cup freshly sliced green onion tops, plus more for garnish (optional); 1 tablespoon freshly ground black pepper, or to taste, plus more for garnish; 1 cup grated Pecorino Romano cheese, or to taste, plus more for garnish