Prepare shallots and garlic and set aside. In a 4-quart stock pot over medium heat, add butter and olive oil. When butter stops foaming, add shallots and garlic. Sauté for one minute, add dry pasta, and sauté for 3 more minutes. Next add chicken broth and bring to a boil. Cover, and reduce heat to simmer pasta until tender. Drain pasta in strainer and place cooked pasta back into original pot, adding heavy cream and cheeses. Stir until cheese is melted.