I got this recipe from http://karmafreecooking.wordpress.com/2008/03/13/top-chef-pasta-bucatini-with-spinach-tomatoes-and-goat-cheese/, and made some modifications. The original recipe is taken from Food & Wine magazine.
Put the spaghetti on boil, partially covered, with about 3 cups water and 1/2 teaspoon of salt.
In a separate pan, heat 1 teaspoon olive oil. Add the grape tomatoes and sautee for 2 minute Add the grated garlic and stir to coat tomatoes with them, about 20 seconds.
Add the chopped spinach, toss with the tomatoes. Cook for about 3 min, until spinach is wilted. Add the basil and stir. Turn off heat and wait until spaghetti is done.
When spaghetti is done, drain about 1/2 cup of cooking liquid from spaghetti into the pan with the spinach and tomatoes and start heat on low. Discard the remaining cooking liquid if any. Add the grated parmesan to the pan and bring to a boil for about 30 seconds, mixing to make sure the parmesan melts.
Pour the contents of the pan into the spaghetti pot and stir over a medium flame until liquid is almost gone, 2-3 minutes. Done!
Tip: The spinach tends to clump together because of the cheese. You can separate it or leave it; the spinach clumps have a nice texture of their own.
Tip: I was surprised to discover this tastes almost as good with no cheese at all. So you can make a much healthier version. It is also tolerant to different amounts of olive oil.