Beef Roasted Tenderloin Recipe

Prep and season

Remove the tenderloin from the refrigerator 30–45 minutes before cooking so it comes to near room temperature. Pat dry with paper towels. Rub the beef with 2 tablespoons olive oil, then evenly season with 2 tsp kosher salt and 1 tsp freshly ground black pepper. Press the minced garlic and chopped rosemary onto the surface so they adhere.

Sear

Preheat oven to 425°F (220°C). Heat a large ovenproof skillet (cast iron preferred) over medium-high heat until very hot. Add 1 tablespoon olive oil if the skillet is dry. Sear the tenderloin on all sides (about 2 minutes per side) until a deep brown crust forms. Add 1–2 tablespoons unsalted butter to the pan during the last 30 seconds and spoon melted butter over the roast.

Roast

Transfer the skillet with the seared tenderloin to the preheated oven. Roast at 425°F for approximately 12–18 minutes for medium-rare (internal temperature 125–130°F / 52–54°C). For medium, roast 18–24 minutes (135°F). Use an instant-read thermometer inserted into the thickest part of the tenderloin to check doneness. Tent loosely with foil and rest for 10–15 minutes; temperature will rise about 5°F while resting.

Finish and slice

After resting, transfer the beef to a cutting board. Slice into 1/2-inch thick medallions. Spoon any pan juices over slices before serving.

While the tenderloin rests (or while it roasts), prepare the potatoes. Wash and dry the potatoes, then cut into 1/2- to 3/4-inch cubes. If using a microwave or steaming, par-cook for 4–5 minutes until just tender (alternatively, start in the cold pan—see note).

Heat a large skillet over medium heat and add 1 tablespoon olive oil and 1 tablespoon unsalted butter. When butter foams, add diced onion and sauté 2–3 minutes until translucent. Add the par-cooked or raw potato cubes in a single layer (work in batches if needed) and increase heat to medium-high.

Let potatoes cook undisturbed for 3–4 minutes to develop a golden crust, then stir and continue cooking, stirring occasionally, for another 6–8 minutes until tender and golden all over. Add minced garlic and thyme in the last 1–2 minutes of cooking and sauté until fragrant.

Season the potatoes with 3/4 tsp salt and 1/2 tsp black pepper. Stir in chopped parsley if using. Keep warm until serving alongside sliced tenderloin.

In a medium bowl, crack 6 eggs and add 3 tablespoons milk or cream, 1 tsp kosher salt and 1/2 tsp black pepper. Whisk until combined and slightly frothy.

Heat a nonstick skillet over medium heat and add 1 tablespoon unsalted butter. When melted and foaming, add the packed spinach (about 4 cups). Sauté 1–2 minutes until wilted, stirring to break down leaves. If the spinach releases excess water, cook until most liquid evaporates (30–60 seconds).

Reduce heat to medium-low. Pour the beaten eggs over the wilted spinach. Let sit undisturbed for 10–15 seconds, then gently stir with a silicone spatula, folding the eggs from the edges toward the center. Continue to cook slowly, folding every 10–15 seconds, until curds form and eggs are just set but still moist — about 2–4 minutes total.

Remove from heat and stir in 1/4 cup grated Parmesan or cheddar if using. Taste and adjust seasoning. Keep warm and serve immediately with the potatoes and sliced beef tenderloin.