How to Make It
In a pot, combine the corn cobs, whole garlic cloves, onion wedges, coriander seeds, bay leaf, 1 teaspoon of salt and 2 quarts of water. Bring to a boil and simmer briskly until the liquid is reduced to 2 cups, 30 minutes. Strain the corn stock and discard the solids; keep the corn stock warm.
In a large skillet, heat the olive oil. Add the bacon and cook over moderate heat, stirring occasionally, until the fat is rendered and the bacon is browned, about 5 minutes. Add the minced onion and cook for 5 minutes, stirring occasionally. Add the minced garlic and cook for 1 minute. Stir in the corn kernels and remaining 1 teaspoon of salt and cook for 2 minutes. Add the warm corn stock and bring to a simmer. Cook until the stock is reduced to 2/3 cup, about 10 minutes. Add the sour cream and simmer until the sauce begins to thicken, about 5 minutes. Stir in the butter. Remove the skillet from the heat and stir in the cilantro and lime zest. Season the corn with salt and serve warm.