Makes 6 sandwiches (6 servings)

An out-of-the-ordinary sandwich for entertaining, try this for brunch, with a side of fresh fruit. Accompany the focaccia with a green salad and serve the sandwich for lunch. To make the omelet more substantial, first sauté vegetables, such as sliced mushrooms, before adding the egg. Herbes de Provence is an excellent seasoning for eggs; but you can substitute about 1 tablespoon minced fresh herbs, such as basil or oregano, or a combination.

For the bread

One 8-inch onion or plain focaccia, halved horizontally

Butter or chèvre cheese, as desired

For the filling

4 eggs

2 tablespoons cold water

1 teaspoon herbes de Provence

1 tablespoon olive oil

1 cup thin onion slices

2 cloves garlic, minced

2 tablespoons butter

1 ½ cups coarsely shredded stemmed fresh salad spinach leaves

½ cup coarsely shredded Romano cheese

1 freshly roasted red bell pepper (or 1 jarred roasted red bell pepper, well drained), cut into ½-inch strips

Dash of freshly ground pepper

Dash of salt

Preheat the oven to 300° F.

Spread the cut sides of the focaccia with the butter or cheese.

To make the filling, lightly whisk the eggs and water, just until blended, in a medium bowl, then whisk in the herbes de Provence; set aside. Heat the oil in a medium nonstick skillet over medium-high heat. Add the onion; cook, stirring constantly, until it is tender and translucent, about 5 minutes. Add the garlic during the last minute. Transfer the mixture to a bowl and cover to keep warm.

Melt the butter in the same skillet over medium-high heat; swirl it to coat the pan, then pour in the egg mixture. Cook undisturbed for about 30 seconds, then as the edges become firm, push them toward the center without cutting through the omelet, so the uncooked portions can reach the hot pan surface. Tilt the pan and move the cooked portions as necessary until the egg is still moist but no longer runny, about 3 minutes. Slide the omelet, without folding it, from the skillet onto the bottom half of the focaccia.

To assemble the sandwich, layer the remaining filling ingredients on the top of the omelet: the cooked onion mixture, spinach, cheese, and bell pepper strips. Sprinkle with pepper and salt. Close the sandwich.

Wrap the sandwich in aluminum foil. Place it on a baking sheet and bake for about 15 minutes, or until the bread is heated through and the cheese is melted.

Use a serrated knife to slice the focaccia into 6 wedges for serving.