Melt butter over medium high heat. Whisk in flour and cook until a blonde roux has formed. Refrigerate roux until cold.
Heat olive oil over medium high heat. Sweat shallots. Once shallots are translucent, add mushrooms and sauté until golden. Add water and Maggi Seasoning and bring to a simmer.
Once broth has come to a simmer, crumble roux into simmering soup. Whisk roux thoroughly into soup. Simmer until soup thickens. Add half and half to thickened soup.
