Preheat a grill on medium-high heat. Place corn cobs and zucchini halves on a baking sheet and drizzle with 1 tablespoon olive oil, salt, and pepper. Grill until charred, about 8 minutes for the zucchini and 10 minutes for the corn. Transfer to a cutting board and let cool. Once cool, cut the kernels off the corncobs and slice the zucchini.
While the grilled corn and zucchini cool, cook the orzo until al dente in a large pot of salted, boiling water. Rinse under cold water to cool and drain well.
In a large bowl, whisk the mayonnaise with the remaining 3 tablespoons of olive oil and the lime juice, shallot, and half of the cilantro. Add the orzo, corn, zucchini and the remaining chopped cilantro and mix well. Season with salt and pepper to taste. Crumble the goat cheese all over the top and serve.
This recipe holds up well in the fridge, so it’s great to make ahead for a party.