Heat oil in a large heavy saucepan over medium heat. Add onion and cook, stirring often, until lightly browned, 6 to 7 minutes. Add corn and garlic; cook, stirring often, until the corn is lightly browned, about 5 minutes. Add broth and simmer until the corn is tender, 12 to 15 minutes. Stir in salt and pepper.

Using a slotted spoon, transfer 1 1/2 cups of the corn mixture to a blender or food processor. Add sour cream and 1/2 cup cooking liquid and process until the mixture is smooth, about 2 minutes. (Use caution when pureeing hot liquids.) Return the puree to the pan.

Whisk in cornmeal; bring the soup to a boil over medium-high heat and cook, whisking constantly, until it thickens. Add bell pepper, scallion, parsley (or cilantro) and hot sauce; heat through. Serve with lime wedges.

Tip: Removing Corn from the Cob: Stand an uncooked ear of corn on its stem end in a shallow bowl and slice the kernels off with a sharp, thin-bladed knife. This technique produces whole kernels that are good for adding to salads and salsas. If you want to use the corn kernels for soups, fritters or puddings, you can add another step to the process. After cutting the kernels off, reverse the knife and, using the dull side, press it down the length of the ear to push out the rest of the corn and its milk.

MAKE AHEAD TIP: Cover and refrigerate for up to 2 days.