Chop the onion finely. Clean and wash the chicken legs. In a pot, heat oil, braise the legs on all sides.
Take them out and put in a baking tray. In the same oil, braise the onions and rice. Once the rice turns glassy, transfer it and the onions to the tray with the legs, sprinkle the crumbled, dry spearmint.
Pour 3 parts water in the pot, season with salt to taste and pour it into the tray. Bake at 284°F (140 °C). Before the rice completely absorbs the water, turn the oven off.