In nonstick fry pan, melt butter with garlic over medium-low heat. Add tomato and red bell pepper; let simmer for a few minutes.
Sprinkle basil over the top while it is simmering. Add milk, reserving 1 tablespoon. Mix reserved milk with flour and add to tomato mixture. Keep stirring while it simmers another 2 minutes until sauce has thickened.
Sprinkle Parmesan cheese and nutmeg on top; stir. Serve over fettuccine noodles.