The blend of olive oil, white wine, lemon juice, herbs and other seasonings favored by Chef Todd Downs fits the standard definition of a marinade. If it also sounds like vinaigrette-with three parts oil to one part acid-well, it is. But the mixture performs several chores when applied as a marinade. Penetrating only about 1/8 inch into the meat, the marinade flavors and crusts the surface when it is seared.
Oil also has a job to do. “Oil coats the pork so that oxygen won't discolor it—and then it helps brown it,” says Stephen Simmons, executive chef of Stratford, an upscale senior residence center in San Rafael, Calif.