Chicken Curry in a Hurry with Basmati

Name: Chicken Curry in a Hurry with Basmati
Ingredients: 1 1/2 teaspoons cumin seed; 1 1/2 teaspoons coriander seed; 1 1/2 teaspoons yellow mustard seed; 1 teaspoon fennel seed; 1 teaspoon fenugreek; 1 teaspoon black peppercorns; 1-inch piece cinnamon stick; A few curry leaves, fresh or dried, if available; 4 to 5 cardamom pods; 1 tablespoon turmeric; 1 teaspoon ground red pepper flake or red chili powder; 1 leek; 1 small onion; 1 to 2 red finger chile peppers, optional; 4 cloves garlic; 1 inch ginger root; 1 apple, large Gala or Honeycrisp; 4 tablespoons butter; A few curry leaves, if available; 3 tablespoons flour; 4 cups chicken stock; 1 1/4 cups basmati rice; 1 rotisserie chicken, 3 to 4 pounds; About 1/3 cup mango chutney, Patak's preferred brand; Salt; 2 store-bought garlic naan bread; Cilantro leaves and 2 scallions, to serve