Smoked Duck Gumbo

Name: Smoked Duck Gumbo
Cuisine: American, Southern, Cajun And Creole
Ingredients: 1 1⁄4 cups canola oil; 1 1⁄4 cups flour; 2 tbsp. freshly ground black pepper; 1 1⁄2 tbsp. granulated garlic; 1 tbsp. granulated onion; 1 tbsp. paprika; 1 1⁄2 tsp. mesquite seasoning, such as McCormick Grill Mates; 1⁄2 tsp. cayenne; 1 large white onion, roughly chopped; 1 medium green bell pepper, roughly chopped; 8 cups duck or chicken stock; 2 1⁄2 lb. smoked duck breast, cut into 1"x2" strips about 1/2" thick; 1 1⁄2 lb. andouille sausage, sliced 1/4" thick on an angle; Cooked white rice, for serving; Sliced scallions, for garnish