Cook the rice then fluff with a fork. Set aside.
In an oil-free pan, dry toast the cardamom pods, mustard seeds and coriander seeds until they emit a nutty aroma. Cool a bit then grind the spices into a paste.
Heat the ghee or clarified butter in a frying pan. Add the spice paste, kaffir lime leaf, lemon zest and turmeric powder. Cook, stirring often, until fragrant.
Add the rice. Stir. Sprinkle with a bit of salt. Cook just until heated through.
Squeeze the lemon over the rice. Stir. Add the fried onion sliced. Stir one last time.