Sprinkle beef with peppercorns & salt, pressing to adhere.
Heat oil in roasting pan, over medium-high heat; sear beef all over.
Roast in preheated 375F oven for about 55 minutes or until meat thermometer inserted in centre registers 140F (for medium-rare); transfer to cutting board, tent with foil & let stand for 15 minutes before carving.
Sauce: Heat 2 tbsp pf the butter in a saucepan over medium heat; cook shallots, stirring occasionally, for about 10 minutes or until softened.
Stir in sugar & cook for an additional 10 minutes or until shallots are golden & caramelized; stir in garlic & thyme and cook for a further 5 minutes.
Add stock, wine, brandy & bay leaf, bring to a boil, then reduce heat and simmer for about 30 minutes or until sauce is reduced to about 2 cups.
Whisk cornstarch with 1 tbsp water, then whisk into sauce and boil until smooth & thickened; discard bay leaf.
Add roasting pan juices to sauce, bring to a boil, then whisk in remaining butter; serve with roast.