Prep the Vegetables:
Begin by shredding the cabbage into thin strips. Chop the onion, tomato, and green chilies (if using). Set these ingredients aside.

Heat the Oil:
In a large pan or wok, heat the vegetable oil over medium heat. Once the oil is hot, add the mustard seeds and cumin seeds. Let them splutter for a few seconds.

Sauté the Aromatics:
Add the chopped onion to the pan and sauté until it turns golden brown. Add the green chilies and ginger-garlic paste. Stir and cook for 1-2 minutes until fragrant.

Add Tomatoes and Spices:
Add the chopped tomato to the pan. Cook for 2-3 minutes until the tomatoes soften. Then, add turmeric powder, coriander powder, and salt. Stir to combine and let the spices cook for another minute.

Cook the Cabbage:
Add the shredded cabbage to the pan. Toss it well to coat with the spices. Cook on medium-high heat, stirring occasionally, for 5-7 minutes until the cabbage becomes tender but still slightly crunchy.

Add Garam Masala (Optional):
If using, sprinkle garam masala on top of the cabbage stir-fry for an extra layer of flavor. Stir well.

Finishing Touches:
Turn off the heat and sprinkle fresh cilantro leaves on top of the stir-fry. For a tangy flavor, add a squeeze of lemon juice. Mix well.

Serve:
Serve your cabbage stir-fry hot with steamed rice, chapati, or naan.