In a pot saute garlic in oil for a few minutes, then add onion and celery. Saute until they are soft. Then add pepper and mushrooms saute a few more minutes. Add tomatoes and sauce and sugar. Cook on medium low for 15 minutes. Add oregano, basil and season to taste with salt and pepper. Remove from heat and cover until needed.
While tomato sauce is cooking, slice zucchini and eggplant into 1/4 inch thick slices. Brush with o.oil and season with s&p. Grill vegetables on med heat until still firm, but grill marks are on both sides. This won't take long so keep your eye on them.
In a pot melt butter on low heat. Add flour and stir well, removing from heat when it starts to brown. Slowly add in milk and cream while stirring vigorously. Place back on heat and add s&p and nutmeg. Remove from heat once sauce it slightly thick.
In a 9x13 baking dish rub a little butter to ensure easy removal of lasagna. Coat the bottom of the dish with a lg spoonful of white sauce. Place your first layer of noodles. Spread tomato sauce on top of pasta and then a layer of eggplant. Add a little tomato sauce to the top of the eggplant and another layer of pasta. Spread the ricotta cheese onto this layer and then another layer of pasta. Spread white sauce onto pasta then place zucchini and more white sauce. Finish with last layer of pasta and tomato sauce. Top with mozzarella and Parmesan cheese.
Cover with tinfoil and place on cookie sheet to catch any spill over. Bake at 400 degrees for 40 minutes. Remove tinfoil and bake another 15 - 20 minutes until top has nicely browned. Let sit for 15 minutes before serving.