Mix together 1 tablespoon of olive oil with 1 teaspoon of salt, the cumin, chipotle powder and paprika. Brush this seasoned oil all over the ears of corn. Grill the corn on high heat for about 10 minutes, turning frequently to ensure all sides get slightly charred. Remove from the grill and allow to cool before handling. When cool, remove the corn kernels from the cob with a sharp knife. Place the kernels in a bowl and set aside for later. Heat the broth in a saucepan over medium heat and keep it at a low simmer while making the risotto. In a large pan, heat the other tablespoon of olive oil over medium heat. Add the shallot and a pinch of salt and sauté for a couple minutes then add the garlic. Sauté for just a minute more and add the dry rice. Sauté the dry rice to toast it for a couple minutes. Add the wine and a half teaspoon of salt and sauté for a minute until absorbed.Add the broth, a ladle at a time to the rice. Stir each ladle into the rice until it is fully absorbed before adding more broth. Repeat this process until all of the broth is added, stirring continuously. The entire process should take about 30 minutes. Turn off the heat. Stir in the sour cream, cotija cheese, lime juice, cilantro and pepitas.