1 eggplant, sliced 1/2-inch thick
1 zucchini, sliced 1/2-inch thick on an angle
1 red bell pepper, quartered lengthwise
1 large portobello mushroom cap
1 red onion, sliced 3/4-inch thick
1/2 cup extra virgin olive oil (EVOO), divided
Salt and pepper
6 ounces baby spinach
1/3 cup pine nuts (a generous handful)
2/3 cup grated Parmigiano Reggiano cheese (a couple generous handfuls)
1 cup store-bought giardiniera (pickled vegetable salad)
1/2 cup pitted green olives
One 8- to 9-inch round loaf crusty bread
1/4 pound deli-sliced provolone cheese
Pre-heat a grill or grill pan to medium-high. Lightly brush the eggplant, zucchini, bell pepper, portobello and red onion with 4 tablespoons EVOO; season with salt and pepper. Cover and grill, turning once, until charred, about 6 minutes.
Using a food processor, puree the spinach, pine nuts and Parmigiano Reggiano cheese; season with salt and pepper. With the machine on, drizzle in the remaining 4 tablespoons EVOO. Transfer the pesto to a bowl; rinse the food processor.
Using the food processor, pulse the giardiniera and olives into a coarse relish.
Slice the top quarter off the bread and scoop out the insides. Spread half the pesto on the inside of the bread, layer with half of the grilled vegetables, then spoon the remaining pesto on top. Fill the bread with the remaining vegetables and top with the provolone. Spread the inside of the bread top with the vegetable relish and set into place. Press down firmly, then cut into wedges.