Meanwhile, heat oil in a large skillet over medium-high heat. Add mushrooms and saute 3 to 5 minutes, until mushrooms soften. Add chicken and thyme and cook 1 minute. Add sherry and cook 1 minute. Add chicken broth and bring to a simmer. Whisk together flour and milk and add to chicken mixture. Simmer 2 to 3 minutes, until sauce thickens.
Remove from heat, add cheese and stir until cheese melts. Add fusilli and toss to combine. Fold in black olives. Serve green beans on the side.