Heat the oven to 350°F. Place the rice and 4 cups of the chicken stock in a heavy-duty Dutch oven. Cover and bake for 45 minutes, until most of the liquid is absorbed and the rice is al dente.
Meanwhile, if using raw broccoli or cauliflower, prepare the broccoli about 10 minutes before the risotto is ready to come out of the oven. Cut the head into florets. Peel the stem and slice it in into "coins" about 1/4-inch thick. Place the prepared stems in a glass bowl and add 1/4-cup water. Cover with a tight-fitting lid. Cook in the microwave until just barely tender, about 3 minutes. Remove from the microwave and add the florets to the partially cooked stems. Cover again and cook in the microwave until the florets are bright green and the vegetables are tender, 3 to 5 minutes. Drain, discarding the water. Set the broccoli aside.
Or, you could also saute mushrooms, asparagus, spinach, or your favorite vegetable. (I would stay away from watery ones such as zucchini or yellow squash.) And, if using previously cooked (aka leftovers) here's the time to heat them up before adding to the baked risotto. Ditto if adding a protein like chicken or seafood - both must be already cooked before adding at the end of cooking the Baked Risotto.
After 45 minutes, remove the risotto from the oven, add the remaining cup of chicken stock, half of the Parmesan, wine, butter, salt, and pepper, and stir vigorously with a wooden spoon or a whisk until the rice is thick and creamy, about 2 minutes. Fold in your vegetable or protein of choice. Top with the remaining Parmesan cheese and return to the oven until melted, about 5 minutes. Serve immediately.