Preheat your oven to 400°F (200°C). Pat the beef roast thoroughly dry with paper towels. This helps achieve a better sear and a delicious crust.

In a small bowl, combine kosher salt, black pepper, garlic powder, and onion powder. Rub the entire roast with olive oil, then generously season with the prepared spice mixture, ensuring all sides are covered.

Heat a large, oven-safe skillet (or Dutch oven) over medium-high heat until very hot. Carefully place the seasoned beef roast in the hot skillet and sear on all sides until a deep brown, caramelized crust forms, about 2-3 minutes per side. This step is crucial for developing rich flavor.

If not using an oven-safe skillet, transfer the seared beef to a roasting pan fitted with a rack. Place the fresh rosemary and thyme sprigs around the roast. Insert a meat thermometer into the thickest part of the beef, ensuring it doesn't touch any bone.

Roast in the preheated oven for 60-90 minutes, or until the internal temperature reaches your desired doneness: 130-135°F (54-57°C) for medium-rare, or 135-140°F (57-60°C) for medium. Keep in mind that the temperature will continue to rise slightly (carryover cooking) while the roast rests.

Remove the roast from the oven. Transfer it to a clean cutting board, tent loosely with aluminum foil, and let it rest for 15-20 minutes. This resting period allows the juices to redistribute throughout the meat, ensuring a tender and moist roast. Do not clean the roasting pan or skillet; it contains the flavorful drippings essential for the au jus.

While the beef is resting, place the skillet or roasting pan (with all the drippings and browned bits) over medium heat on the stovetop. If using, pour in the dry red wine and deglaze the pan, vigorously scraping up any browned bits (fond) from the bottom of the pan with a wooden spoon. Let the wine reduce slightly, about 2-3 minutes.

Add the beef broth, Worcestershire sauce, minced garlic, and bay leaf to the pan. Bring the mixture to a gentle simmer and cook for 10-15 minutes, allowing the liquid to reduce by about a third and the flavors to concentrate and meld beautifully.

Carefully pour the au jus through a fine-mesh sieve into a clean saucepan, pressing firmly on any solids in the sieve to extract maximum flavor. Discard the strained solids and the bay leaf.

For optional thickening: In a small bowl, whisk together the cornstarch and cold water until a smooth slurry forms. Bring the strained au jus back to a gentle simmer over medium-low heat. Gradually whisk in the cornstarch slurry and cook, stirring constantly, for 1-2 minutes until the jus is slightly thickened to your desired consistency. Avoid boiling vigorously after adding cornstarch to maintain clarity.

Slice the rested beef against the grain into desired thickness (thin for sandwiches, thicker for a main course). Serve immediately with the warm, savory au jus on the side for dipping or drizzling over the meat.