Cut the mushrooms in halves. Heat the oil in a pan and add the mushrooms. Stir fry the mushrooms for 5 minutes or until fully cooked.  Add the spinach to the mushrooms. Simmer for another 10 minutes or until spinach is fully cooked.  Add the KFI Rogan Josh Sauce and simmer for an additional 5 minutes.  Garnish with finely sliced ginger or chopped cilantro. Serve with naan bread.