To Make the Sandwich:
1. Preheat a grill to medium-high.
2. Place the eggplant slices on a wire rack and sprinkle them lightly with salt on both sides. Set the rack aside until the eggplant begins to “sweat,” usually 15 to 20 minutes.
3. Meanwhile, brush all sides of the peppers with some of the olive oil. Grill the peppers, turning them occasionally,
until they are blistered and lightly charred on all sides. Place them in a bowl, cover it tightly with plastic wrap, and set it aside to steam while you grill the remaining vegetables.
4. Cut the onions into 1/2-inch-thick rounds, and then insert toothpicks horizontally through the slices to hold them together on the grill. Pat the eggplant slices dry with paper towels. Brush both sides of the eggplant, zucchini, yellow squash, and red onion slices with the remaining olive oil and place them on a large baking sheet or platter. Season with kosher salt and black pepper to taste. Grill the vegetables, in batches if necessary, until they are lightly charred on the edges and nicely marked on both sides, 10 to 15 minutes. Transfer the grilled vegetables to a platter and set it aside.
5. Slide the skins off the bell peppers and discard the cores and seeds. The peppers should separate into nice wide strips. (Rinse the peppers in a little water if necessary to remove any excess charred skin.) Add the peppers to the platter with the other vegetables.
6. In a small bowl, combine the goat cheese, garlic, extra-virgin olive oil, and basil, and stir until well combined. Season to taste with kosher salt and black pepper.
7. Lightly toast the ciabatta slices, just to warm them through, either on the grill or in a toaster.
8. Assemble a sandwich by drizzling some of the vinaigrette (recipe follows) over one side of a slice of ciabatta and generously spreading some of the goat cheese mixture over one side of a second slice. Arrange an assortment of grilled vegetables over the vinaigrette-coated slice, and then drizzle with more vinaigrette if desired. Top the mound of vegetables with the second slice of bread, goat cheese side down, and press gently to form a sandwich. Cut it in half. Repeat with the remaining bread, vinaigrette, cheese mixture, and veggies. Serve immediately. (Any unused grilled vegetables can be stored in an airtight container in the refrigerator for up to 4 days. Use them in sandwiches or salads.)
Yield: 6 to 8 sandwiches, depending on the size of the ciabatta
To make the Vinaigrette:
Whisk the vinegar, olive oil, sugar, and garlic together
in a small bowl. Season to taste with kosher salt and pepper.
Yield: 3⁄4 cup