To do pot-in-pot cooking, you will need a tall trivet and a stainless steel container that you can use within the main pot. You can make rajma chawal together in the Instant Pot with brown rice using the pot-in-pot method. . Brown rice similar to kidney beans, cooks in 25 minutes. White rice cooks very quickly so that will not work in this recipe. It will get overcooked if cooked for that long. You can cook white rice separately. However, if you are using canned red kidney beans, then you can cook white rice with it in the Instant pot using the pot-in-pot method. Alternatively, you can also add the brown rice directly into the Instant Pot along with the rajma. Add water accordingly and make rajma chawal together.