Prepare a grill or grill pan for medium-high heat. Brush the corn and bell pepper with oil and grill, turning occasionally, until charred and tender, 6 to 8 minutes for the pepper and 12 to 15 for the con. Transfer the grilled vegetables to a cutting board as they are finished and let cool slightly.

Brush 3 of the lime halves with oil, you won't need the 4th half, save for another use. Grill the halves, cut side down, rotating occasionally, until charred, about 5 minutes. Transfer the limes to a plate.

To make the vinaigrette, thinly slice the garlic, then mount the salt on top. Using both the blade and flat side of a chef's knife, chop and scrape the mixture into a paste. Transfer to a small bowl or jar. Juice the grilled limes and add the lime juice and shallot to the bowl with the garlic and whisk in the oil.

Cut the corn kernels from the cobs and roughly chop the bell pepper. Arrange the grilled vegetables, tomatoes, cucumber, and radishes in a large bowl. Add the vinaigrette and a generous pinch of salt and pepper; gently toss to combine. Sprinkle with the cheese and herbs to serve.