Grilled Vegetable Sandwich with Herbed Ricotta

ricotta cheese

each of fresh basil, chives and parsley, chopped

garlic, minced

extra virgin olive oil plus more for drizzling

kosher salt and freshly ground black pepper

portobello mushroom

medium zucchini, sliced lengthwise

medium yellow squash, sliced lengthwise

medium eggplant, sliced into rounds

red onion, peeled and sliced into rounds

red bell pepper, seeded and sliced in half or quarters

dried oregano

loaf ciabatta bread or other soft bread sliced into 6-inch sections and cut in half

arugula leaves

Balsamic glaze