Grilled Vegetable Sandwiches

2 tablespoons olive oil
2 medium-size zucchini, scrubbed, trimmed and sliced lengthwise in 1/8-inch-thick strips
2 baby eggplant, white or purple, washed, trimmed and halved lengthwise
2 large red onions, peeled and cut into 1/8- to 1/4-inch thick slices
10 to 15 large fresh basil leaves
4 hoagy or submarine rolls, preferably semolina

4 sandwiches

Prepare grill.
Brush vegetables lightly with one tablespoon or less of the olive oil on both sides.
Grill zucchini 10 to 12 minutes, depending on thickness, turning several times; grill eggplant 6 to 8 minutes, turning; grill onion 6 to 8 minutes, turning.
Arrange vegetables in layers on flat plate, sprinkling remaining olive oil over them, interspering the layers with basil leaves. Allow to sit at room temperature for a few hours for flavors to meld.
If possible, use without refrigerating, but if refrigeration is necessary, return to room temperature before making into sandwiches.
Slice rolls lengthwise, but not completely through. Pull out the excess bread in the middle and fill with vegetables.