Cook pasta in a large saucepan of boiling water until tender; drain.
Meanwhile, heat oil in a medium frying pan over medium heat; cook and stir shallots and garlic until soft. Add mushrooms; cook, stirring, until tender. Stir in cream and sage. Cook and stir for 5 minutes or until thickened. Season to taste with salt and pepper.
Toss sauce with pasta; serve with crusty bread, if desired.