Bring a large pot of lightly salted water to a boil. Cook lasagna noodles in boiling water for 8 to 10 minutes, or until al dente. Drain, and cut noodles in half crosswise.
Melt margarine in a skillet over medium heat. Saute garlic just until fragrant. Stir in the flour until no lumps remain. Gradually mix in milk, and season with thyme. Simmer sauce gently until thick. Remove from heat.
Grease a 9x9 inch glass baking dish. Layer noodles, sauce, asparagus, ham, and mozzarella cheese in three layers, each starting with noodles, and ending with shredded cheese on the top.
Cover the dish, and cook in the microwave on HIGH for 9 to 10 minutes, or until cheese is melted and bubbly. Time may vary depending on the oven used. Let stand for 5 to 10 minutes before serving.