EGGPLANT LASAGNE WITH PARSLEY PESTO

Steps:

• Make béchamel:
• Cook garlic in butter in a 3-quart heavy saucepan over moderately low heat, stirring, 1 minute. Add flour and cook roux, whisking, 3 minutes. Add milk in a stream, whisking. Add bay leaf and bring to a boil over moderately high heat, whisking constantly, then reduce heat and simmer, whisking occasionally, until liquid is reduced to about 4 cups, about 10 minutes. Whisk in salt and white pepper, then remove from heat and discard bay leaf. Cover surface of sauce with wax paper until ready to use.
• Make pesto and ricotta mixture:
• Coarsely chop 1/3 cup hazelnuts and reserve for sprinkling over lasagne.
• Purée parsley, Parmigiano-Reggiano, 2/3 cup oil, garlic, 1 teaspoon salt, 1 teaspoon pepper, and remaining cup hazelnuts in a food processor until pesto is smooth, about 1 minute.
• Whisk egg in a bowl, then stir in ricotta, 1 cup parsley pesto, remaining teaspoon salt, and remaining 1/4 teaspoon pepper until combined well.
• Stir together 1/4 cup pesto and remaining 1/4 cup oil in a small bowl for drizzling over lasagne.
• Roast eggplant for lasagne:
• Put oven racks in upper and lower thirds of oven and preheat oven to 450°F. Oil 2 large baking sheets.
• Brush eggplant with oil on both sides, then arrange in 1 layer on baking sheets and sprinkle with salt and pepper. Bake eggplant, switching position of sheets halfway through baking and turning slices over once, until tender, 20 to 25 minutes total.
• Assemble lasagne:
• Put oven rack in middle position and reduce oven temperature to 425°F. Lightly oil a 13- by 9- by 2-inch glass or ceramic baking dish (3 quart) and line a larger shallow baking pan with foil.
• Spread 1 cup béchamel in baking dish and cover with 3 pasta sheets, leaving spaces between sheets. Drop 1 cup ricotta mixture by spoonfuls over pasta, spreading evenly (layer will be thin), then top with 1 layer of eggplant, cutting rounds to fit if necessary. Make 1 more layer each of béchamel, pasta, ricotta, and eggplant. Spread with 1 cup béchamel and cover with remaining 3 pasta sheets. Spread remaining cup ricotta mixture over pasta, then spread ricotta with remaining cup béchamel and top with remaining eggplant in 1 layer (you may have a few slices left over). Sprinkle Parmigiano-Reggiano over eggplant and scatter with reserved chopped hazelnuts.
• Tightly cover baking dish with oiled foil (oiled side down), then set dish in foil-lined pan (to catch drips) and bake lasagne 30 minutes. Remove foil and bake until golden and bubbling, 10 to 15 minutes more. Let lasagne stand 15 to 20 minutes before serving.
• Serve lasagne drizzled with pesto.