Tendons, Marrow, Cartilage and Fat Become Popular Ingredients

On his debut menu at Parallel 37 in San Francisco’s venerable Ritz-Carlton, Michael Rotondo featured a pillowy Asian steamed bun that proved to be a sensation from the get-go. But nestled inside the clamshell-shaped bao was not the usual suspect of pork belly.

Instead, in its place was a chicken foot that had been braised, dehydrated, fried—and astonishingly—completely deboned. With the skills of a surgeon, a cook had spent six...