For speedy preparation of these sandwiches, use a jar of your favorite meatless spaghetti sauce. My favorite is "tomato-basil," and I add a pinch of red pepper flakes for a little zest.

One 14-ounce jar marinara sauce

Eggplant-Parmesan Filling
1 egg

1 tablespoon water

½ cup packaged herb and garlic-seasoned dried bread crumbs

2 tablespoons olive oil

½ eggplant (about 8 ounces), peeled and cut into twelve ¼-inch-thick crosswise slices (see Tip)

To complete the recipe
Four 6- to 8-inch poor boy (sub or hoagie) buns, halved horizontally

Mayonnaise for spreading

2 cups coarsely shredded stemmed spinach leaves

½ cup (2 ounces) freshly grated Parmesan cheese

Preheat the oven to 375° F. Heat the marinara sauce in a small saucepan over medium heat, stirring occasionally.

To make the filling: Beat the egg lightly in a shallow bowl; stir in the water. Pour the bread crumbs into a separate shallow bowl. Heat 1 tablespoon of the oil in a large nonstick skillet over medium heat until a drop of water bubbles when dropped in. Dip several eggplant slices, one at a time, into the egg, then press both sides into the bread crumbs. Cook until browned on the bottom; turn and cook until browned on the second side and tender, about 4 to 5 minutes per side. As you remove the slices from the skillet, place them on a paper towel-covered plate, and cover to keep warm. Repeat with the remaining eggplant slices, adding the remaining 1 tablespoon oil as needed, until all are cooked.

While cooking the last batch of eggplant slices, arrange the buns, cut-sides up, on a baking sheet and toast in the oven for about 4 minutes, or until the cut surfaces are lightly browned.

Spread mayonnaise on the cut surfaces of each bun. Layer each bottom half with spinach and 3 overlapping eggplant slices. Drizzle with marinara sauce and sprinkle with parmesan cheese. Top each sandwich with an upper bun half, mayonnaise-side down.