Firstly, wash the basmati rice 2–3 times until the water runs relatively clear.
Now soak the rice in enough water for 15–20 minutes.
Coarsely grind the ginger and garlic together and set aside.
Heat 1 tablespoon oil and fry the sliced onions until light golden and caramelized. Remove and set aside.
Peel and score the baby potatoes. If using regular potatoes, cut them into medium-sized chunks.
Now place the potatoes in a bowl. Toss the potatoes with turmeric - 1/4 tsp, red chilli powder - 1/2 tsp, cashews - 10 and 1 tablespoon oil. Mix it well.
Heat the same pan used to fry the onions.. Stir-fry the potatoes for 4–5 minutes until lightly golden. Remove and set aside.
Take a large mixing bowl. Add 2 tablespoons curd and whisk until smooth. Then add kasoori methi 1 tsp, turmeric powder - 1/4 tsp, red chilli powder - 1 tsp, biryani masala - 2 tsp, fried onions, 4 -5 slit green chillies, fresh mint leaves, salt to taste, garam masala poowder- 1/2 tsp and 1 teaspoon ghee. Mix everything well.
Add the fried potatoes and mix until evenly coated. Marinate for 15–20 minutes.
Boil approximately 4 cups water with 1 bay leaves, 2 green cardamom, 1 small piece of cinnamon, salt , ½ teaspoon ghee and mint leaves.
Now add the soaked rice and cook until approximately 80% cooked. Drain immediately.
Heat 2 tablespoons oil in a heavy-bottomed pot. Add 1 green chilli and 1 tbsp ginger-garlic paste and sauté until fragrant.
Add the marinated potatoes and remaining marinade. Add approximately ½ cup water and mix gently.
Spread the 80% cooked rice evenly over the potato layer.
Drizzle ghee over the rice and top with fried onions and fresh mint or coriander.
Cover tightly and cook on low heat for 10 minutes.
Place the pot on a tawa and continue dum cooking on low heat for another 15 minutes.
Turn off the heat and let the biryani rest, covered, for 5–10 minutes.
Gently fluff the rice and serve hot with onion raita, cucumber salad and lemon wedges.