Ingredients

• 3 tablespoons olive oil
• 1 small onion, finely chopped
• 2 garlic cloves, chopped
• 2 (28-ounce) cans whole tomatoes in puree, pureed in a blender until smooth
• 1/2 teaspoon salt
• 3/4 teaspoon black pepper
• 6 pounded, pre-cooked breaded chicken breast halves (from the deli counter)
• 4 (12-inch-long) loaves Italian bread, halved lengthwise
• 1 (12-ounce) jar marinated artichokes, drained
• 1 pound fresh mozzarella, thinly sliced
• 1/2 cup finely grated Parmigiano-Reggiano (1 1/2 ounces)

Instructions

1. Heat olive oil in a 4 to 5-quart heavy saucepan over moderately high heat until hot but not smoking; then cook onion, stirring occasionally, until golden, about 5 minutes. Add garlic and cook, stirring, 1 minute. Add tomato puree, salt, and pepper and simmer, uncovered, stirring occasionally, until slightly thickened, about 30 minutes.
2. Preheat oven to 400 degrees F.
3. Arrange bottom halves of bread loaves on a large baking sheet and tops on another large baking sheet, all with cut sides up. Spread 1/4 cup tomato sauce on each top and bottom. Divide chicken between bottom halves. Top each (open-faced) sandwich with 1/4 cup tomato sauce, 1/4 of the artichokes, 1/4 of the mozzarella, and sprinkle with some of the Parmesan.
4. Bake open-faced sandwiches in lower third of oven until cheese melts, about 3 minutes. When cheese begins to melt, put tops of loaves in upper third of oven and bake until edges are golden, 3 to 4 minutes (watch tops closely; they burn easily). Put tops on bottoms to make sandwiches, then slice into serving pieces.
5. Cooks' note: Tomato sauce can be made 3 days ahead and chilled, covered. Reheat before using.