Tamale Pie with BBQ Pulled Pork

Name: Tamale Pie with BBQ Pulled Pork
Ingredients: 3 pounds Boneless Pork Shoulder Roast; 1 cup Spicy Barbecue Sauce, Divided; 1 whole Sweet Onion; 1 whole Poblano Pepper; 1 whole Yellow Bell Pepper; 1 whole Orange Bell Pepper; 2 Tablespoons Olive Oil; 2 teaspoons Kosher Salt; 2 teaspoons Chili Powder; 1 teaspoon Cumin; 1 can (14.5 Oz. Size) Fire Roasted Diced Tomatoes; 2 boxes (8.5 Oz. Size) Jiffy Corn Muffin Mix; 2 whole Eggs; ⅔ cups Milk; 2 cups Shredded Sharp Cheddar Cheese; 2 cups Corn Kernels (frozen Or Canned Is Fine); Sour Cream, For Serving