Roast beef tenderloin with Thai-style gravy

Trim the tenderloin to an even piece (tuck the tapered tail under if roasting that end).

Salt liberally and, optionally, leave uncovered on a rack in the fridge for as many hours as possible, up to overnight, to dry the surface.

Truss the roast with twine, looping and tightening about an inch apart, and tie off.

Pepper liberally with black pepper.

Insert a leave-in probe thermometer in the centre and set the alarm to 125F, 10 degrees under the 135F target, for carryover cooking.

Oven sear at 450F for 10 minutes.

Reduce to 275 and roast low and slow until the alarm sounds.

Gravy: brown ground beef in a little oil, deglazing with a little beef stock if it sticks.

Add chopped shallots and cook until well caramelized and soft; deglaze with the rest of the stock.

Simmer 15 minutes to infuse the beef flavour, then strain.

Season with fish sauce, soy sauce and sweet soy sauce; thicken with a flour-and-water slurry a little at a time, not too thick.

Add chopped garlic, sliced lemongrass and Thai chilies; turn off the heat and let the residual heat infuse. Finish with lime juice and taste.

Cover the roast in foil and rest about 15 minutes, until the probe temperature starts to drop (it reached 135F).

Remove all the twine and slice; serve with mashed potato and the gravy finished with chopped cilantro.