Ingredients

• 2 tablespoons plus 2 teaspoons balsamic vinegar
• 3/4 teaspoon kosher salt plus more
• 2 cloves garlic, minced
• 1 1/2 teaspoons finely chopped rosemary leaves
• Freshly ground black pepper
• 1 cup extra-virgin olive oil
• 1 yellow bell pepper, seeded and quartered
• 1 red bell pepper, seeded and quartered
• 1 pound zucchini, cut on a diagonal into slices about 5 inches long and 1/4-inch thick
• 1 pound eggplant, cut on a diagonal into slices about 5 inches long and 1/4-inch
• 3 medium portobello mushrooms, stemmed, dark gills removed, sliced 1/4-inch thick
• 1 medium red onion, cut into 1/4-inch thick slices
• 1 large vine-ripened tomato, cut into 1/4 inch slices
• 1/2 pound fresh or smoked mozzarella, cut into 1/8 inch thick slices, or 4 ounces fresh goat cheese cut into 8 pieces
• 1 cup arugula or basil leaves, washed and dried
• One 9-inch square piece of focaccia bread, about 1 to 1 1/4 pounds

Instructions

1. In a small bowl, whisk together the vinegar, 3/4 teaspoon salt, garlic, rosemary, and pepper. Gradually whisk in 1/2 cup of the oil to make a dressing. Set aside.
2. Preheat a stove top grill pan or out-door grill to medium heat. Brush the peppers, zucchini, eggplant, mushrooms, and onion with the remaining oil. Grill the peppers until lightly browned and tender, about 5 minutes per side. Transfer the peppers to a pan or large platter. Grill the zucchini, until softened and lightly browned and tender, about 3 minutes per side; transfer to the pan with the peppers. Grill the mushrooms, until soft but not flabby, about 2 minutes per side; set aside with the other vegetables. Grill the onions until soft, about 5 minutes per side; set aside with the other vegetables. Drizzle a tablespoon of the dressing over the vegetables and season with salt and pepper to taste.
3. To make the Dagwood sandwich: Split the bread in half to make two evenly thick square pieces. Brush the dressing on the cut sides. Make a layer of each of the grilled vegetables that evenly covers one piece of the bread, overlapping the pieces slightly, if necessary. Top with a layer of the tomatoes, season with salt and pepper. Lay the arugula on top and drizzle them with about a tablespoon of the dressing. Finish the sandwich off with the cheese and lay the other piece of bread on top. Wrap the sandwich tightly in plastic wrap. Place the wrapped sandwich on a cutting board or baking sheet and weigh it down with a heavy object, such as a cast-iron skillet, for about 1 hour. When ready to serve cut into 4 to 6 pieces equal pieces.