Shred the drained, squeezed jackfruit with your fingers into a large bowl, discarding any tough core pieces. Stir in the yogurt, ginger-garlic paste, chili powder, coriander, garam masala, turmeric, lemon juice and 1 1/2 tsp salt. Cover the rinsed rice with cold water and add the saffron threads to the warm oat milk. Let everything sit for 30 minutes.
Heat the oil in a 26 cm / 10-inch Dutch oven over medium heat. Add the onions with a pinch of salt and cook for 12 minutes, stirring often, until deep golden brown. Move about half the onions to a plate for topping.
Add the marinated jackfruit to the pot with the remaining onions. Cook over medium heat for 15 minutes, stirring now and then, until the yogurt thickens and oil pools at the edges. Stir in half the mint and cilantro, then smooth the surface and turn off the heat.
When the jackfruit goes in, bring the 2 L of water, 1 tbsp salt, bay leaves, cinnamon, cardamom, cloves and cumin to a boil in a 24 cm / 9.5-inch pot. Drain the soaked rice, add it, and boil for 6 minutes, until a grain snaps with a small white dot in the center. Drain well in a fine-mesh sieve.
Spoon the rice over the jackfruit in an even layer. Scatter the reserved onions, remaining mint and cilantro and the green chilies on top, then drizzle with the saffron milk.
Cover the pot with foil, pressing it around the rim, then set the lid on top. Cook on the lowest heat for 20 minutes. Turn off the heat and let it stand, still covered, for 10 minutes.
Remove the lid and fluff gently from the edges with a fork. Serve right away, scooping from the bottom so the jackfruit and rice mix in each portion.