Grilled Vegetable Panini

1/4 cup olive oil
2 small Japanese eggplants or 1 medium to large regular eggplant, cut crosswise into 1/2-inch-thick slices
2 zucchini, cut crosswise into 1/2-inch-thick slices
1 small red onion, cut into 1/2-inch-thick slices
salt and freshly ground black pepper
2 baguettes
1/2 cup basil pesto
8 ounces fresh water-packed mozzarella cheese, drained, sliced
2 tomatoes, sliced
1/2 cup roasted red peppers
8 large basil leaves

Heat a grill pan over medium-high heat. Drizzle the oil over the eggplant, zucchini, and onion slices, then sprinkle with salt and pepper. Working in batches, grill the eggplant, zucchini and onions until they are tender and grill marks appear, about 4 minutes per side. Cool completely.

Cut each baguette into 6 pieces. Working with one baguette piece at a time, slice in half and spread both sides with pesto. Working with the bottom slice, stack 2 slices of eggplant, 2 slices of zucchini, 1 slice onion, 1 slice tomato, 1 slice mozzarella, and 1 slice of roasted red pepper. Sprinkle with salt and pepper. Place top half of baguette on top and grill.