Bring a large saucepan of lightly salted water to a boil. Cook lasagne noodles in boiling water for 8 to 10 minutes or until al dente. Drain and cut lasagne in half crosswise.
Melt margarine in a frypan 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 square 22cm glass baking dish. Layer noodles, sauce, asparagus, ham and mozzarella cheese in three layers each starting with noodles and ending with grated 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.