Heat sufficient oil in a kadai and deep-fry boris till golden. Drain on absorbent paper and set aside. In the same oil, deep-fry brinjal cubes till golden. Drain on absorbent paper and set aside.
Heat one tablespoon oil in a non-stick pan, add fennel seeds, cumin seeds, mustard seeds and let the seeds splutter. Add onion and sauté till it becomes translucent. Add ginger-garlic paste and saute for a minute.
Add spinach, fried boris, fried brinjal and salt. Mix well, cover and cook for a few minutes or till the spinach wilts. Serve hot.