1. Cook pasta in boiling water to cover over medium-high heat 6 to 7 minutes. Drain and keep warm.
2. Bring milk to a boil in a medium saucepan over medium-high heat. Remove saucepan from heat.
3. Melt butter in another medium saucepan over medium heat. Whisk in flour and nutmeg, and cook 1 minute or just until flour is light brown. Whisk in hot milk. Bring to a boil, whisking constantly. Reduce heat to low, and add Gorgonzola cheese; stirring until melted. Remove from heat.
4. Sauté shallots in hot oil in a large skillet over medium-high heat 5 minutes or until golden. Add spinach and tomatoes; cook 3 minutes or just until spinach is barely wilted. Season with salt and pepper to taste.
5. Toss together pasta, Gorgonzola mixture, and shallot mixture. Pour into a lightly greased 13- x 9-inch baking dish. Sprinkle with 1/4 cup Parmesan cheese.
6. Bake at 350° for 15 to 20 minutes or until bubbly. Garnish, if desired.