1. Have ready a microwave-safe baking pan, such as an 8-inch square glass pan. Bring a medium pot of water to a boil. Sprinkle in about 1 tsp. salt, then add spaghetti and cook until al dente, about 8 to 9 minutes. Drain and transfer to the baking pan.
2. While the water heats and the spaghetti cooks, prepare the vegetables. Place a steamer insert in a second medium pot with about 1 inch water. Bring water to a boil and add the broccoli and cauliflower. Steam just until al dente, about 2 to 3 minutes. Transfer to the baking pan. Add the sweet potatoes to the steamer and steam until just barely tender, about 8 to 10 minutes. Transfer to the pan. Mix to combine vegetables and spaghetti.
3. Empty the water from the steaming pot, add butter, and melt over medium heat. Sprinkle flour on the butter and whisk until well combined — it should be a paste-like texture. Add milk a few tablespoons at a time, whisking constantly. The consistency should thicken slightly to coat the back of a spoon after 5 to 7 minutes. Do not bring to a boil. Stir in salt and pepper and 1 cup of the cheese until melted and sauce is smooth, about 30 to 45 seconds. Sauce should be the consistency of thin pancake batter. Pour sauce over vegetables in pan and mix to combine.
4. Arrange slices of apple or pear over the vegetables, then sprinkle surface with remaining 1 cup cheese.
5. Cook in microwave on high until cheese is bubbly and beginning to brown, about 10 minutes. Let rest 2 minutes, then serve hot.
Source: Hannaford fresh Magazine, September - October 2011