Cook pasta according to package directions, omitting any salt or oil.
Drain and set aside. 

In a large nonstick skillet, heat butter and oil and sautée mushrooms, green onions, parsley, and garlic over medium heat for about 5-7 minutes, or until tender. In a bowl, combine cornstarch with about 1/2 cup milk, and mix until smooth. Add to the pan and stir continuously. 

Gradually add wine and remaining milk, stirring until mixture thickens. Reduce heat and add spinach and crabmeat, stirring until spinach is wilted.
Season to taste. 

Toss with pasta and sprinkle with Parmesan cheese before serving.

Serve Hot.