Roast Beef with Potato Gratin, Baby Potatoes, and Herb Butter Jus

HEADNOTE:
This dish is built on precision: beef roasted to a controlled pink center, potatoes cooked in two distinct forms, and cream and cheese used only where they sharpen the dish’s richness. The result should feel composed and complete, with the tenderness of the meat set against the quiet weight of the gratin and the clean finish of herbs and black pepper.

RECIPE ESSENTIALS:
Dish category: Main course
Cuisine or origin: Classic European
Course type: Dinner
Yield: 1 portion
Serving size: 345 g
Prep time: 20 minutes
Cook time: 35 minutes
Total time: 55 minutes
Difficulty: Intermediate

EQUIPMENT:
Small sauté pan
Small roasting tray
Shallow gratin dish, 12 cm
Saucepan
Sharp knife
Cutting board
Fine grater
Kitchen paper
Instant-read thermometer

INGREDIENTS:
Beef

Beef, trimmed loin or sirloin: 180 g

Salt: 2 g

Black pepper, freshly ground: 1 g

Olive oil: 8 g

Potato gratin

Potato, peeled: 90 g

Onion, finely sliced: 25 g

Garlic, finely grated: 3 g

Heavy cream: 45 g

Cheese, finely grated: 18 g

Butter: 8 g

Salt: 1 g

Black pepper, freshly ground: 0.5 g

Baby potatoes

Potato, baby potatoes, scrubbed: 70 g

Butter: 6 g

Olive oil: 4 g

Herb, finely chopped: 2 g

Salt: 1 g

Black pepper, freshly ground: 0.5 g

METHOD:

1. Heat the oven to 190°C. Lightly butter the gratin dish and the roasting tray. Bring a saucepan of salted water to a simmer for the baby potatoes.

2. For the gratin, slice the potato very thinly, no thicker than 2 mm. Toss it with the onion, garlic, cream, cheese, butter, salt, and black pepper. Pack the mixture neatly into the gratin dish. The surface should be level and the cream should just rise through the layers.

3. Bake the gratin for 25 to 30 minutes, until the top is golden, the cream has reduced, and the potato yields without resistance when pierced. The edges should be set and lightly browned, not dry.

4. While the gratin bakes, season the beef evenly with salt and black pepper. Heat the olive oil in a sauté pan over high heat until just shimmering. Sear the beef for 2 minutes on the first side, 1 to 2 minutes on the second, and 30 seconds on the remaining sides. Transfer to the roasting tray and roast for 6 to 8 minutes for medium-rare, or until the center reaches 52°C to 54°C.

5. Rest the beef for 8 minutes on a warm board. The flesh should relax and remain supple; the juices must settle before slicing.

6. Cook the baby potatoes in the simmering water for 10 to 12 minutes, until just tender at the center but still intact. Drain well and return them to the warm saucepan for 1 minute to dry their surface.

7. Add the butter, olive oil, herb, salt, and black pepper to the potatoes. Toss gently over low heat for 1 minute until the potatoes are glossed and the herb clings evenly. They should remain whole, with a clean, buttery finish.

8. Slice the beef against the grain into neat portions. Spoon the gratin from the dish with a firm edge so the layers remain visible. Arrange the baby potatoes beside the meat and finish with any buttery herb glaze from the pan.

PLATING AND SERVING:
Place the gratin as a compact base or side mound, not spread across the plate. Set the sliced beef in a clean line beside it, then gather the baby potatoes to one side so the plate reads with structure and restraint. Serve immediately while the beef is warm, the gratin is creamy beneath its browned surface, and the potatoes remain glossy.

PROFESSIONAL NOTES:
Do not overfill the gratin dish; the cream must reduce, not boil over. The beef should be seared aggressively but roasted gently to preserve tenderness. Keep the baby potatoes whole and dry before glazing so the butter and herb coat them evenly rather than slipping away.