Preheat the oven to 450 F for the cauliflower. Toss the cauliflower with a tablespoon of vegetable oil and the chaat masala. Spread over 2 cookie sheets and roast for 20 minutes or so, until browned and fragrant. Continue with the other preparations while they are roasting.
Add the farro to the drained bean liquid along with enough water to cover by 3-4 inches. Bring to a boil. Let cook for 10-15 minutes, until almost cooked through and add the corn kernels. Cook for another 5 minutes, until the corn and farro both are cooked through. Drain and set aside.
Add the drained cooked beans to the cooked onions, fishing out the whole spices if desired.