Preheat the grill to 450℉-500℉.
Place the corn directly on the grill, rotating it every few minutes to ensure even cooking. Close the lid between turns. Cook for 10 minutes or until the corn is tender but not shriveled. Remove the corn and allow it to cool for 5 minutes.
Once cooled remove the kernels from the cob.
Place 6 cups of broth in a large saucepan over medium heat. Throw the naked cobs into the broth with the lid on and simmer for 10 minutes. *For optimal corn flavor, keep the cobs in the broth throughout the entire risotto cooking time. You will need to strain the broth before adding it to the rice, but you can strain it as you go.
While the cobs are simmering in the broth, add 3 tbsp of butter to a wide pot or pan over low heat. Once melted add in the shallot and cook for 2-3 minutes.
Next add the rice and toast for 3-4 minutes until the grains start to become translucent.
Add the first round of strained corn infused chicken broth. Depending on the pan add broth until it just covers the risotto. (could be 1 cup to 1 1/2 cups). Give it a quick mix, a shake of the pan to ensure all grains are covered and cook until rice absorbs the majority of the broth. Mix 2-3 times each round of broth. Don't worry if you mix more. It terms of salting, after the first round taste it (avoiding the rice), if it needs salt start with a heavy pinch (1/4 tsp) and go from there.
Add more broth and repeat above steps. This recipe calls between 4-5 cups of broth. If you notice that it is perfectly cooked at 4, don't add more. This part of the recipe really takes intuition and feeling, if the rice is still hard or hard for your liking then add more little by little.
On the last broth addition, introduce the corn. When the risotto has absorbed the majority of this broth and is al dente (if it isn't al dente yet, continue adding broth), turn off the heat. Fold in the mascarpone cheese and another tablespoon of butter. Serve immediately.