Rack of Lamb with Herb Crust

Frenching refers to the trimming of a rack of lamb in which all meat, fat, and sinew is scraped away from the upper portion of each rib bone, leaving the bones completely bare and clean. The practical purpose is aesthetic: the exposed white bones create the classic presentation of individual chops with a clean handle. Frenching has no effect on flavour — the bones themselves contribute negligible flavour to the meat during the short roasting time. Most supermarkets sell pre-frenched racks; a butcher can french an un-trimmed rack for you on request. If buying already frenched, check that the fat cap on the loin meat has been trimmed to a thin 3 to 5 mm layer — too much fat on top prevents the mustard and crust from adhering properly.

For medium-rare — the standard for rack of lamb in restaurant cooking — pull the rack from the oven when the thickest part of the eye of meat reads 52 to 54°C (125 to 130°F) on an instant-read thermometer. It will rise to 57 to 60°C during the 10-minute rest, which is the ideal serving temperature for medium-rare. For medium: pull at 57°C (135°F), rest to 63°C. For well-done: pull at 65°C (150°F). Rack of lamb should never be served well-done — the meat becomes tight, dry, and loses its characteristic flavour. The colour at medium-rare is uniformly rose-pink throughout the eye, with no grey ring.

The preparation can be staged effectively. The herb crust can be made up to 24 hours ahead and refrigerated. The racks can be seasoned, seared, and mustard-coated up to 4 hours before the dinner — refrigerate after searing, then apply the crust 20 minutes before you intend to roast (bringing the rack to room temperature). Do not apply the herb crust before refrigerating — the breadcrumbs absorb moisture and become soggy. The final roasting and resting must happen just before serving: rack of lamb does not reheat well and loses the medium-rare doneness and the crispness of the crust.

Panko breadcrumbs are Japanese-style breadcrumbs made from bread without crusts and processed to produce larger, flakier, more irregular flakes than European-style breadcrumbs. These larger flakes create more surface area exposed to the oven heat, crisping to a dramatically lighter, crunchier texture than the dense, uniform coating of standard breadcrumbs. On rack of lamb, the textural contrast between the crackling panko crust and the soft, yielding lamb underneath is a significant part of the dish's appeal. Regular breadcrumbs can be substituted but will produce a denser, less crunchy crust.

In classical French cuisine, rack of lamb is served with a red wine jus — the natural juices from the roasting pan deglazed with red wine and veal or lamb stock, reduced to a glossy, intensely flavoured sauce. Accompaniments include dauphinoise potatoes (gratin with cream and garlic), haricots verts (French green beans briefly blanched), and flageolet beans (the traditional French accompaniment to lamb). The colour of mint — mint sauce, mint jelly, or a mint and pea purée — is also a classic pairing, particularly in British tradition. The acid note of mint or a lemon-dressed vegetable cuts through the richness of the meat and the buttery crust.