This is the holiday-worthy dinner that LOOKS impossibly fancy but actually takes just 1 hour to make. Beef tenderloin with roasted potatoes takes a beef tenderloin (filet) generously seasoned with salt, pepper, garlic, and rosemary, sears it on all sides in a hot cast iron skillet, then roasts it to a perfect medium-rare at 425°F — served sliced with crispy garlic-rosemary roasted baby potatoes and herb compound butter melting on top.
Fun fact: beef tenderloin (also called filet mignon when cut into individual steaks) is the most tender cut of beef because the muscle it comes from doesn’t do any work. Cattle barely use their tenderloin muscle, so it develops no toughness. The cut accounts for only 2% of a cow’s total weight, which is why it commands the highest price per pound. The classical French preparation is exactly what we’re doing here.
Why this recipe works
SEASON HEAVILY. Tenderloin is mild — needs aggressive seasoning. Use 1.5x the salt you think.
SEAR THEN ROAST. Crispy crust comes from screaming-hot cast iron. Even cooking comes from gentle oven heat. Both are essential.
REST 10 MINUTES. Slicing immediately loses all juices. 10 min rest = juicy slices.
Preheat oven to 425°F (220°C). Pat tenderloin completely dry. Season ALL sides generously with salt, pepper, garlic powder, and onion powder. Let sit at room temp 20 min.
Step 2: Start potatoes first
Toss halved baby potatoes with olive oil, smashed garlic, rosemary, salt, and pepper. Spread on a sheet pan, cut-side DOWN. Roast 25 minutes.
Step 3: Sear the tenderloin
While potatoes roast, heat 1 tbsp olive oil in a large oven-safe cast iron skillet over HIGHEST possible heat until smoking. Sear tenderloin 2 min per side (4 sides total = 8 min) until deeply golden brown crust all around.
Step 4: Roast the tenderloin
Transfer skillet to the oven (with potatoes still in there). Roast 20-25 minutes until internal temp is 125°F for medium-rare (will rise to 130°F as it rests). Use a meat thermometer — this is non-negotiable for perfect doneness.
Step 5: Make herb butter (while roasting)
Mix softened butter with minced garlic, parsley, thyme, and salt. Set aside.
Step 6: Rest and serve
Remove tenderloin to a cutting board. Spread herb butter over the top while still hot — it’ll melt and coat the meat. Let rest 10 min (essential for juicy slices). Slice against the grain into 1/2-inch slices. Plate with the crispy roasted potatoes. Spoon any pan juices over the slices.
Nutrition information
Calories: 540 kcal per serving
Protein: 38 g
Carbohydrates: 30 g
Fat: 28 g
Iron: 30% DV
Vitamin B12: 60% DV
Pro tips for the best beef tenderloin with roasted potatoes
Use a MEAT THERMOMETER. 125°F for medium-rare (recommended), 130°F medium, 140°F medium-well. Don’t guess.
Cast iron > regular skillet for the sear — retains heat better, gets crustier. If no cast iron, sear in stainless steel.
Trim silver skin before seasoning — the white connective tissue makes meat chewy. Slip a sharp knife under and slice it off.
Make the herb butter ahead — even better after 2 hours of flavor development.
Frequently asked questions
How do I tell when it’s done?
ONLY by internal temperature. 125°F medium-rare, 130°F medium. Color is unreliable. Insert thermometer in the thickest center part.
Can I cook it ahead?
Best served right after resting. To prep ahead, sear and trim 2 hr ahead, refrigerate. Roast just before serving.
What if my tenderloin is bigger or smaller?
2 lb = 20-25 min. 3 lb = 30-35 min. Add 5 min per pound. ALWAYS check internal temp instead of relying on time.
This recipe is for tenderloin specifically. For other cuts (ribeye roast, sirloin) adjust temp and time — those cuts have different shapes and densities.
