Spinach, Pesto, and Fontina Lasagna

Melt butter in heavy large saucepan over medium heat. Add flour and whisk 1 minute (do not brown). Add milk and wine and whisk until smooth. Cook until sauce thickens and comes to boil, whisking constantly, 4 to 5 minutes. Remove from heat. Whisk in Parmesan cheese and salt. Season sauce to taste with pepper. DO AHEAD: Sauce can be made up to 1 day ahead. Cover and chill.

Heat oil in large pot over medium-high heat. Add shallots and garlic. Sauté until shallots soften, about 2 minutes. Add all spinach (pot will be full). Cook spinach until wilted but still bright green, tossing often, about 3 minutes. Using tongs, transfer spinach to large sieve set over bowl; reserve pot. Press out excess liquid from spinach. Drain 10 to 15 minutes longer.

Return drained liquid from spinach to reserved pot. Boil until liquid is reduced to glaze. Return spinach to pot and toss 1 minute. Remove spinach from heat. Mix in 1 1/2 cups sauce. Season spinach to taste with pepper.

Place noodles in large bowl. Fill bowl with hot tap water. Soak noodles until pliable, stirring occasionally to separate, about 15 minutes. Place large sheet of parchment paper on work surface. Transfer noodles to parchment in single layer, shaking off excess water.

Preheat oven to 350°F. Butter 13 x 9 x 2- inch glass baking dish. Mix ricotta, Parmesan, and lemon peel in medium bowl. Season to taste with salt. Mix in egg.

Spread 1/2 cup sauce thinly over bottom of prepared dish. Top with 3 noodles, arranged side by side and covering most of bottom of dish. Spread half of spinach mixture over (about 1 1/2 cups). Sprinkle with 1/3 cup Fontina. Top with 3 noodles and half of ricotta mixture (generous 1 3/4 cups). Drop half of pesto over by teaspoonfuls, spacing drops evenly apart. Continue layering with 3 noodles, remaining spinach mixture, 1/3 cup Fontina, 3 more noodles, remaining ricotta mixture, then remaining pesto. Top with last 3 noodles. Spread remaining sauce over; sprinkle with remaining Fontina. Cover dish with buttered foil.

Bake lasagna until heated through and bubbling at edges, 50 to 55 minutes. Remove from oven. Remove foil from dish.

Preheat broiler. Broil lasagna until top is browned in spots, turning dish occasionally for even browning, about 4 minutes. Let stand 15 minutes to set up.

Available at some supermarkets and at specialty foods stores and Italian markets.