Prepare the Ingredients: Clean and slice the mushrooms and bell peppers. Chop the onions, tomatoes, garlic, and ginger.
Cook the Aromatics: Heat oil in a kadai or large skillet. Add cumin seeds and let them splutter. Sauté the onions until golden brown. Add garlic and ginger, and cook for 1-2 minutes.
Add the Spices: Stir in the ground coriander, cumin, red chili powder, and turmeric. Cook for 1-2 minutes until aromatic.
Cook the Vegetables: Add the chopped tomatoes and cook until they soften. Add the sliced mushrooms and bell peppers, and cook for 5-7 minutes until tender.
Finish the Dish: Sprinkle garam masala and salt to taste. Garnish with fresh cilantro and serve hot.