Heat a large skillet and coat with oil. Add mushrooms and sauté for two minutes. Add onions and carrots and sauté for two minutes. Add cabbage and sauté for two more minutes and then remove from heat.
Melt 2 1/2 tablespoons butter in skillet. Add flour and sauté for 30 seconds until lightly browned. Mix in curry powder and salt. Then slowly add water, stirring constantly. Cook while stirring for 1 minute and then add panir and cook for 1 minute more. Now combine panir-curry mixture with the fried vegetable mixture in a large bowl. Heat 1 tablespoon butter in a skillet. Fry pita halves for 1 to 2 minutes on each side, remove from skillet and open into pouches with a knife. Repeat until all pita is cooked and then allow to cool. Stuff the pita with the panir-vegetable mixture. Serve hot or cold. Great for crowd.