Beef Fillet Recipe

1. Day 1 — Roast bones & make stock

Preheat oven to 220°C (425°F). Spread beef/veal bones on a roasting tray, roast 40–60 minutes until deeply browned, turning once. In a large stockpot, combine roasted bones, carrots, onions, celery and tomato paste; cook briefly to caramelize tomato paste. Add red wine and reduce by half over medium heat. Add cold water to cover, bay leaves, thyme and peppercorns. Bring to a gentle simmer, skimming foam for the first 30 minutes. Simmer very gently 6–8 hours, topping up with water to keep bones covered. Strain stock through fine sieve, cool and refrigerate overnight.

2. Day 2 — Reduce to demi-glace

Skim off any solidified fat from chilled stock. Return strained stock to a wide saucepan and simmer slowly to reduce by about two-thirds until syrupy (this can take 6–10 hours depending on quantity). Strain again through fine cloth into a clean pot. Cool and refrigerate. (If making a shorter version, reduce high-quality beef stock by half to concentrate.)

3. Service day — Finish sauce

Remove chilled demi from fridge, skim off any fat. Reheat gently and whisk in butter to give shine and roundness. Adjust seasoning with salt. Keep warm at low heat; if too thick, whisk in a splash of warm stock or water to reach pourable consistency.

4. Place cubed celeriac and potato in a pot and cover with cold water plus 1 tsp salt. Bring to a simmer and cook until very tender, about 20–25 minutes. Drain well and return to warm pot to dry for 1–2 minutes over low heat. Pass through a food mill or blend in a high-speed blender until very smooth. Warm cream and butter together; while blending, stream in warm cream-butter mixture until purée is silky. Season with white pepper and additional salt to taste. Keep warm, cover to prevent skin forming.

5. Using a mandoline or sharp knife, slice peeled celeriac into very thin slices (1–2 mm). Pat slices dry with paper towel. Toss lightly in cornstarch to coat, shaking off excess. Heat neutral oil in a deep pan to 175°C (350°F). Fry celeriac in batches until golden and crisp, about 2–3 minutes per batch. Remove to a rack or paper towel and sprinkle with salt immediately. Keep crisp in a warm oven (100°C/210°F) on a rack until plating.

6. Blanch baby carrots, turnips and asparagus tips separately in salted boiling water until just tender (carrots 4–6 minutes, turnips 3–5 minutes, asparagus 1–2 minutes depending on thickness). Shock in ice water to retain color where appropriate, then reheat in a sauté pan with 30 g butter, a pinch of sugar and 1/2 tsp salt to glaze briefly until shiny and heated through. For peas, blanch for 1 minute, shock, then sauté quickly in a small knob of butter with lemon zest and a pinch of salt to finish. Keep vegetables warm, toss with 1 tsp olive oil just before plating to add sheen.

7. Bring beef fillets to room temperature for 30–45 minutes. Pat dry with paper towels and season all over with 2 tsp salt and 1 tsp freshly ground black pepper. Heat a heavy skillet (preferably cast iron) over high heat until smoking. Add 2 tbs neutral oil and sear fillets 2–3 minutes per side for medium-rare depending on thickness (about 3–4 cm thick). In the last minute of cooking, add 2 tbs butter, thyme sprigs and smashed garlic to the pan and baste the fillets continuously with the butter for color and flavor. Transfer fillets to a resting tray and rest for 6–8 minutes under loose foil.

8. Warm the demi-glace and spoon a small pool onto each plate. Place a generous quenelle or spoonful of celeriac purée slightly off-center. Slice or place the rested beef fillet atop or beside the purée. Arrange glazed baby vegetables and peas artistically alongside. Add 2–3 crispy celeriac chips leaning against the fillet for crunch. Spoon warm demi-glace around the meat (not all over the chips to keep them crisp). Finish with a knob of butter melted into the sauce if desired and garnish with microgreens or chervil and a light drizzle of olive oil over vegetables.

9. Serve immediately so beef is warm, purée silky, vegetables glazed and crispy celeriac remains crunchy.