Make the most of summer veggies with this easy BBQ side dish.
Heat grill to medium-high.
In large bowl, whisk together lemon juice, 2½ tablespoons oil and 1/2 teaspoon each salt and pepper; stir in shallot. Fold in tomatoes and beans. Let marinate while grilling vegetables.
In medium bowl, toss zucchini with remaining 1/2 tablespoon oil and 1/2 teaspoon salt. Place corn and zucchini, cut sides down, on hot grill. Cover and grill zucchini until grill marks appear, 3 to 4 minutes, then flip and cook 1 minute more. Grill corn until lightly charred and cooked through, turning occasionally, 10 to 12 minutes. Transfer vegetables to cutting board as they finish cooking.
When cool enough to handle, cut zucchini in half lengthwise, then chop into 1/2-inch pieces. Cut corn kernels from cobs (you should have about 2 cups). Add zucchini and corn kernels to bowl with tomatoes and toss to combine, then fold in basil. Serve at room temperature or chilled.