Collect pan drippings: After roasting beef tenderloin, remove the meat and set aside to rest. Pour the drippings into a medium saucepan.
Sauté aromatics: Melt butter in the pan and sauté shallots and garlic until soft and fragrant.
Deglaze: Add red wine or ½ cup beef broth to deglaze the pan, scraping up browned bits.
Make roux: Stir in flour gradually, whisking constantly until smooth. Cook for 1–2 minutes to remove raw flour taste.
Add seasonings: Mix in Dijon mustard, Worcestershire sauce, thyme, and smoked paprika.
Simmer: Slowly whisk in remaining beef broth, simmering until gravy thickens to desired consistency.
Finish: Remove from heat and stir in heavy cream or crème fraîche. Taste and adjust seasoning with salt and pepper.
Strain (optional): For a smooth, polished gravy, strain through a fine mesh. Serve hot over sliced beef tenderloin.