Chunky Tuna Chowder Recipe

Name: Chunky Tuna Chowder Recipe
Ingredients: 2 6-ounce cans tuna, drained; 1/2 cup chopped onion; 2 tablespoons trans-fat-free margarine; 1 15-ounce can cannellini beans, rinsed and drained; 1/2 cup sliced celery; 1/2 cup corn kernels; 1 cup peeled carrots (chopped into 1/2-inch pieces); 2 cups water; 1 bay leaf; 1/2 teaspoon dried thyme; 1/2 teaspoon dried basil; 2 teaspoons garlic powder; 1/2 teaspoon ground black pepper; 2 cups nonfat milk (divided); 1/4 cup all-purpose flour; 1/4 cup fresh parsley (chopped and divided)