Among chefs it's widely accepted that food should look good, as well as taste good. Only the most dedicated of home cooks will ever be able to replicate a trained chef's elegant plate arrangements, but not all techniques require such a high level of skill. Frenching a cut of meat, for instance -- trimming it to leave a clean, attractive length of bone -- is a straightforward process that upgrades any dish's appearance. Consider lamb shanks as an example. They're usually slow cooked in a rich sauce, and if left untouched they're simply an undistinguished hunk of meat. If they're frenched, the length of exposed bone gives each portion a distinct visual upgrade.
You could think of shanks as "Leg of Lamb: The Sequel." A shank is simply the ankle portion of each leg, with shanks from the hindlegs providing slightly meatier portions than those from the forelegs. They're filled with dense muscle and tough connective tissue, so they must be braised or stewed for hours before they're tender enough to eat. They're well worth the effort, though, because the finished shanks have a remarkably rich flavor and lush, soft texture.
Some parts of the shank are covered in a thin grey sheath of tough tissue, referred to as silverskin. Peel that off with a sharp knife before cooking or frenching the shanks. Trim away any surface fat, as well. You'll notice that one end of the shank is thicker and meatier, and the other is relatively thin. This thin end is where the tendons attach, and it's where you'll french the shank.
Slide the tip of a small, sharp knife -- a paring knife or a flexible boning knife -- between the tendons and the bone. Slice toward the end of the bone, severing its connections to the tendon. Insert the knife again between the bone and the next segment of tendon, and sever it the same way. Keep going until you've loosened the tendons around the bone's entire circumference. Next, use the tip of your knife to free another inch or so of shank from around the bone. When you cook the shank, the meat and tendons will contract naturally. Without the tendons anchoring them to the bone, the edible portion will simply shrink away and leave the bone bare.
For a neater appearance you can trim away the top half inch of flesh and tendon, leaving a neat horizontal surface around the bone. The trimmed-off piece can go into the pot with your shank to add its flavor to the cooking liquids.
Frenching the shank like a chef requires a few additional steps, now that you've come this far.
Pull the meat away from the bone and cut down another inch or so, sliding your knife along the bone to clean it neatly. At this stage the two shank bones -- one thick, one thin -- should be clearly visible.
Turn the shank over, so you're looking at the thick end. Cut between the two bones with your knife tip, and then loosen the meat around the thin bone. Reverse the shank, so you're handling its thin end again.
Run your knife between the two bones, separating the thin bone from the thick one.
Grasp the thin bone firmly and give it a twist, and then a pull. As it separates slightly from the rest of the shank, use your knife tip to free meat from the small bone.
Repeat, until you can remove the small bone entirely.
Now, when you cook the shank, the tasty lamb will pull away and leave behind just a large, visually striking piece of bare bone.