You begin, as usual, by soaking the salt cod for up to 24 hours in several changes of water. Drain the cod, pat it dry, and cut it into serving pieces.
Now make your sauce, in a skillet or flame-proof baking pan, by very lightly sautéing a soffritto of chopped garlic and parsley in olive oil until it just begins to give off it fragrance. Immediately add roughly chopped very ripe tomatoes (or, the in winter, canned tomatoes) and simmer gently. When the tomatoes start to melt into a sauce, toss in a handful each of capers—preferably the salt-packed kind, rinsed and dried—and olives—preferably the small black Gaeta or Niçoise variety.
While the sauce is simmering, lightly flour and fry your baccalà pieces in olive oil until they are lightly browned. As they brown, transfer them to the pan or skillet with the sauce. When all the baccalà has been added to the sauce, take a spoon and nap a bit of the simmering sauce over the fish pieces.
Now you have a choice: you can continue simmering the dish over the stove, or you can place the dish in a hot oven (200°C, 400°F) for 10-15 minutes, until the sauce has reduced to a nice consistency. I like the oven method, as serving the baccalà direct from its baking dish makes for an attractive presentation at table.
Remove the dish from the oven, sprinkle with a bit more chopped parsley for color, and serve with some nice, crusty bread.