Osteria Novecento is by far the best restaurant in the area. I would go here at the beginning of your trip because you will likely want to visit it a second time before you go. The restaurant features typical umbrian fare but with a gourmet delivery. We’ve never had anything bad here and have tasted most things on the menu. They also have specials that change regularly. It is a small restaurant so you will definitely want reservations if you are a large group or if it is a weekend. The waitress speaks some English. It has a couple of outdoor tables but no real view. It is cozy in the winter with an indoor fireplace.
From Casa Grifone it’s about a 20-minute drive. You go across the highway exit opposite of Todi and toward a little borgo called Ilci.