To the now empty skillet, melt 2 tablespoons butter with 1 tablespoon oil. Add shallots and sauté over medium-high heat for 2-3 minutes to soften.
Reduce heat to low, add garlic and red pepper flakes and sauté for 30 seconds. Add flour and cook for 1 minute, scraping up the browned bits on the bottom of the pan.
Slowly whisk in beef broth and all remaining gravy ingredients. Whisk until most of the lumps are gone.