Eggplant:
1/2 cup sun dried tomato pesto (store bought or follow the link to recipe)
Cut puff pastry into 3 3×9-inch pieces. Place on baking sheet and bake according to package directions. Cool, then gently split each piece in half lengthwise so you have 6 3×9-inch pieces. Set aside.
While the pastry is baking start caramelizing the onions. In large skillet, heat 2 tablespoons olive oil, add onion and salt and cook over medium low heat for about 20 minutes or until onion is very tender and golden, stirring often.
While the onions are cooking, prep the eggplant. Brush eggplant slices with 2 tablespoons olive oil and sprinkle with salt and pepper. Arrange slices on baking sheet and bake at 400 degrees for 5 to 10 minutes until just tender.
Combine cheeses; set aside.
Assembly:
Arrange 3 bottom halves of puff pastry on a baking sheet. Top each piece with a layer of eggplant slices, spread with a thin layer of pesto, then a thin layer of cheese mixture, then some of the caramelized onion, ending with another layer of eggplant brushed with the pesto. Repeat the layer.
Bake at 350 degrees until hot and cheese is melted.
You can assemble the napoleons up to the point just before baking and keep refrigerated until ready to bake. You may need to add about 5 minutes to the cook time if they are very cold.
Make individual Napoleons for a dinner buffet or first course. Simply cut puff pastry into 9 individual 3×3 inch squares and then layer as above.