Heat the ghee or butter in a medium saucepan or Dutch oven over medium heat.
Add the diced onion and minced garlic and sauté for 10 minutes, until very soft and translucent. 2.
Stir in the turmeric, ground coriander, cumin seeds, and cayenne pepper.
Cook for 2 minutes, stirring constantly, until the spices are very fragrant. 3.
Add the cubed eggplant and toss well to coat in the spices.
Cook for 2 minutes, then add the diced tomatoes and salt.
Stir everything together, cover the pan, and simmer for 25 minutes, or until the eggplant is very tender.
Remove the cover for the last 5 minutes of cooking to allow the sauce to thicken. 4.
Stir in the frozen peas and lemon juice.
Cook for 2-3 minutes more, just until the peas are heated through and bright green.
Serve immediately.