Rinse the basmati rice until the water runs mostly clear.

Bring a large pot of salted water to a boil.

Add the rice and frozen lima beans. Parboil until the rice is partly cooked but still firm in the center, about 6 to 7 minutes.

Drain the rice and lima beans. Do not add more salt later, as the rice and beans have already absorbed salt from the water.

Add 3 tablespoons oil to the bottom of a nonstick pot.

Add a packed layer of the rice and lima bean mixture to the bottom of the pot. This will form the tahdig, the crispy rice layer.

Add a loose layer of rice and lima beans, then sprinkle with dried dill. Continue layering rice and dill, ending with dill on top.

Cover and steam over medium-low heat for 10 minutes.

Drizzle the remaining 2 tablespoons oil over the top. Cover the lid with a clean kitchen towel, place it back on the pot, and continue steaming over low heat for 30 to 40 minutes.

To serve, gently spoon the fluffy rice onto a platter, then scrape up the crispy tahdig from the bottom and scatter it over the top.