A butter mushroom curry with fresh vegetables in a tomato gravy. Kadai Mushroom is such a super easy and delicious dish of sautéed button mushrooms, onions, bell peppers (capsicum) in a spiced, tangy tomato sauce. The recipe comes together in 30 minutes and so delish with naan, roti and even bread rolls. Mushrooms, spices, onions, tomatoes and bell peppers – their combination never goes wrong.