Rinse the basmati rice under cold water until the water runs clear, then soak it for 20 minutes.
Drain the rice and set aside.
Heat oil in a pan over medium heat.
Add mustard seeds and let them splutter.
Stir in urad dal and sauté until golden brown.
Add slit green chilies and sauté for a minute.
Mix in the drained rice and turmeric powder, stirring gently.
Add 2 cups of water and salt to taste, and bring to a boil.
Once boiling, reduce the heat to low, cover, and cook for 15 minutes.
Once cooked, fluff the rice with a fork and mix in lemon juice.