To cook the tenderloin, preheat the oven to 400 degrees F. Oil a roasting pan or ovenproof skillet with 1 tablespoon olive oil. When oil is hot, sear the tenderloin on all sides, about 5 minutes total. Transfer pan to the oven and cook until it registers 118 degrees F for rare. (Should be about 28 minutes but check around 20 minutes so you don't overcook it.)

Transfer tenderloin to a platter and tent loosely for about 10 minutes. Save the pan so you can deglaze it for the mushroom sauce. (See Mushroom Sauce instructions.)

For the mushroom sauce you 2 choices. You can make it ahead a few hours, let it stand at room temperature and reheat while tenderloin is resting, or you can start it when you put the tenderloin in the oven.

Heat the 3 Tbsps oil in a large skillet. Sauté the mushrooms about 8 minutes over high heat. Add the shallots, remaining pressed garlic clove and remaining teaspoon thyme. Cook another 2 minutes. Stir in 2 Tbsps of the brandy and cook 1 minute. Add the cream and cook about 3 minutes. Most of the liquid should be absorbed. (If making ahead set the mushroom mixture aside at this point. Rewarm while tenderloin is cooking and then pick up with the following instructions.)

Sprinkle flour over the mushroom mixture and stir to coat.

With the remaining 2 Tbsps of brandy, deglaze the tenderloin roasting pan over medium heat, scraping up any brown bits. Add to the mushroom mixture.

Add the Beef reduction or demi-glace to the mushrooms and bring to a boil. Simmer on medium high heat about 5 minutes until slightly thickened. Add remaining teaspoon of thyme. Season with salt and pepper to taste.

Slice tenderloin and spoon mushroom sauce over slices.

Preheat oven to 450 degrees F. Oil bottom of a roasting pan, Place meat in pan and scatter onions and carrots around shanks. Roast about 25 minutes. Transfer beef and vegetables to a large dutch oven. Deglaze the roasting pan with the brandy, scraping up the brown bits. Transfer to the dutch oven with the meat and vegetables. Add the broth and the thyme sprigs.

Bring to a boil and then reduce heat so it simmers for about 2 ½ hours until liquid is reduced to about 2 cups. Strain out solids. (You can make this up 4 days ahead keeping it in the fridge. When ready to use remove any fat from the surface.)