Heat the olive oil in a pan over medium-high heat. Add the onion rings and garlic, cook for 2-3 minutes. Add the curry powder and sauté for 1 minute. Add the broth and rice, bring to a simmer, then cover and remove from heat. Let stand for 5 minutes. Season the chicken legs with salt, pepper, and paprika.
Transfer the rice mixture to a large baking dish. Add the mango, papaya, spring onions, kidney beans, and prawns. Season with salt, pepper, and chili powder. Mix well.
Place the chicken legs on top, skin-side down. Bake at 190°C (374°F) on the middle rack for 45-50 minutes. Turn the legs skin-side up halfway through. The chicken is done when it reaches 74°C (165°F) internally. If the top browns too much, stir the rice gently and cover loosely with foil.